Memoirs: The Genital Organs of Stylaria lacustris, with an account of thier Development

1924 ◽  
Vol s2-68 (269) ◽  
pp. 147-186
Author(s):  
H. R. MEHRA
Keyword(s):  
Body Wall ◽  
Vas Deferens ◽  
Ejaculatory Duct ◽  
Body Cavity ◽  
The Body ◽  
Yolk Mass ◽  
Sperm Duct ◽  
Prostate Cells ◽  
Stylaria Lacustris ◽  
Columnar Cells

1. The genital organs of Stylaria lacustris are described in detail. The vas deferens opens into the atrium on the anterior face near the opening of the ejaculatory duct and not at the top as described by all the previous authors. The prostate surrounds not only the atrium but also the vas deferens in segment 6. 2. The prostate secretion passes through the atrial epithelium, which consequently hypertrophies and disappears 3. The development of the genital organs proceeds with great rapidity when the sexual phase appears, which occurs only once a, year from the end of September to the beginning of December. There is no long intervening period between the development of the gonads, and other genital organs. 4. The order of development seems to be connected with the time or order of their functioning. 5. The gonads are peritoneal in origin. The sperm-sac and orisac are large portions of the body-cavity enclosed by the extension backwards of septa ⅚ and 6/7 respectively. The yolk-mass is formed by a process of metabolic change in the cytoplasm of some of the ova. 6. The sperm-duct is partly peritoneal in origin and partly an ectodermal invagination. The funnel and the vas deferens rudiments arise by a proliferation of the peritoneal cells on the anterior face of septum ⅚, which assumes the form of a deeply shining plate of columnar cells with prominent nuclei. This after the funnel rudiment becomes the sperm-cord and penetrates the septum in front of the ovary, reaching near the body-wall the atrial rudiment, which is soon formed as an ec todermal invagination. The prostate cells arise from the peritoneum near the rentral body-wal1 of the sixth segment in the neighbourhood of the atrial rudiment. 7. The rudimentary female funnel, which opens ont at the female opening, arises as, an outgrowth from the peritoneum at the base of septum 6/7. 8. The spermatheca srises as an invagination from the ectoderm. I agree with Bergh that the sperm, zthecae are to be considered as new structures, and not phylogenetically connected with the genital ducts as Gatenby supposes to be the case in Tubifex rivulorum. 9. A fern stages obtained showing the development of these organs in Nais e1inguis confirm the above observntions.

Morphological descriptions of the egg and larval stages of Trichuris suis Schrank, 1788

Parasitology ◽  
1973 ◽  
Vol 67 (3) ◽  
pp. 263-278 ◽  
Author(s):  
R. J. S. Beer
Keyword(s):  
Reproductive System ◽  
Intestinal Tract ◽  
Vas Deferens ◽  
Ejaculatory Duct ◽  
The Body ◽  
Vitelline Membrane ◽  
Initial Development ◽  
Larval Stages ◽  
Trichuris Suis ◽  
System L

The egg and larval stages of Trichuris suis can be briefly characterized as follows: The egg: barrel shaped, possesses a thick shell consisting of three thick outer layers and an inner thin vitelline membrane, is operculate at each end and is unsegmented and unfertilized when freshly deposited. L. 1 within the egg: presence of an oral spear, a poorly denned oesophagus and an intestinal tract consisting of undifferentiated granulated material. L. 1 within the host: initial differentiation of an oesophagus, cell body, intestine and rectum. L. 2: further differentiation of the body organs and the appearance of the rudiments of the reproductive system. L. 3: initial development of reproductive system and development of a cloaca in the male thus distinguishing the sexes. L. 4: differentiation of reproductive system into vagina, uterus, oviduct and ovary in the female, and testis, vas deferens, ejaculatory duct, spicule and spicular muscle, sheath and tube in the male. L. 5 or adult stage: completed development of the sexual organs including formation of the vulval orifice and eggs in the female and seminal vesicle in the male.

scholarly journals Pulmonary Mechanics and the Work of Breathing in the Semi-Aquatic Turtle, Pseudemys Scripta

1986 ◽  
Vol 125 (1) ◽  
pp. 137-155 ◽  
Author(s):  
Timothy Z. Vitalis ◽  
William K. Milsom
Keyword(s):  
Body Wall ◽  
Striated Muscle ◽  
Work Of Breathing ◽  
Body Cavity ◽  
The Body ◽  
Mechanical Work ◽  
Pulmonary Mechanics ◽  
Pump Frequency ◽  
Elastic Forces ◽  
Pseudemys Scripta

Measurements of pulmonary mechanics on anaesthetized specimens of the aquatic turtle Pseudemys scripta (Schoepff) indicate that the static pulmonary mechanics of the total respiratory system are determined primarily by the mechanics of the body wall rather than those of the lungs. This is also true under the dynamic conditions of pump ventilation at low pump frequencies. As pump frequency increases, the work required to inflate the multicameral lungs of the turtle begins to contribute an increasing portion to the total mechanical work required to produce each breath as measured from pressure volume loops. The rise in the work performed on the lungs results from an increase in the non-elastic, flow-resistive forces which must be overcome during ventilation. The primary bronchus to each lung is the most likely site of flow resistance. There is also a small elastic component to the work required to ventilate the lungs associated with movement of the intrapulmonary septa and the striated muscle surrounding the lungs. The contribution of the work required to distend the body cavity as a percentage of the total mechanical work required to generate each breath remains relatively unchanged with increasing ventilation frequency, indicating that the majority of the forces to be overcome in the body wall are elastic in nature. For a constant rate of minute pump ventilation, as frequency increases, the work done per minute to overcome elastic forces decreases, while that done to overcome non-elastic forces begins to rise. These opposing trends produce an optimum combination of pump volume and frequency at which the rate of mechanical work is minimum.

scholarly journals Studies on sperm storage in the vas deferens of the spinifex hopping mouse (Notomys alexis)

Reproduction ◽  
2003 ◽  
pp. 233-240 ◽  
Author(s):  
EJ Peirce ◽  
HD Moore ◽  
CM Leigh ◽  
WG Breed
Keyword(s):  
Vas Deferens ◽  
Core Body Temperature ◽  
Laboratory Mouse ◽  
Body Cavity ◽  
Sperm Storage ◽  
The Body ◽  
Cool Temperature ◽  
Main Site ◽  
Cauda Epididymidis ◽  
Common Laboratory

The cauda epididymidis, with its relatively cool temperature (32-35 degrees C), is considered to be the main site of sperm storage in male mammals. However, in the adult male spinifex hopping mouse, Notomys alexis, similar numbers of spermatozoa are found in the vas deferens to those in the cauda epididymidis. The present study shows that, unlike in the laboratory mouse in which spermatozoa of the vas deferens are found mainly in the epididymal region of the duct, spermatozoa in the hopping mouse are localized mainly to the middle and urethral regions of the vas deferens which lies in the inguinal and lower abdominal region of the body cavity. After ligation of the vas deferens close to its connection with the epididymis, many spermatozoa in the vas deferens retain the potential for motility for up to 2 weeks, indicating that the viability of spermatozoa is not compromised by being restricted to core body temperature. This urethral region of the vas deferens, in which spermatozoa reside, has a highly divergent structural organization compared with that of common laboratory rodents in which there is an expanded lumen with a network of epithelial folds. Ultrastructural observations of the cells lining the duct indicate that there are not any marked differences in morphology compared with the cells lining the duct in common laboratory murids, but the infoldings of the vas deferens of the hopping mouse are highly vascular which might facilitate supply of oxygen and nutrients to the spermatozoa residing in the lumen.

scholarly journals I. The Croonian lecture. —“ Observations on the locomotor system of echinodermata

1881 ◽  
Vol 32 (212-215) ◽  
pp. 1-11 ◽  
Keyword(s):  
Short Distance ◽  
Body Wall ◽  
Body Cavity ◽  
The Body ◽  
Considerable Time ◽  
Tube System ◽  
Radial Canal ◽  
Locomotor System ◽  
Direct Pressure ◽  
Stone Canal

In Holothuria the polian vesicle opens freely into a wide circular canal a short distance from the termination of the stone canal. From this circular canal five lozenge-shaped sinuses project forwards, and from each of these two large oval sinuses run forward parallel with each other─the ten oval sinuses becoming continuous with the hollow stems of the tentacles. Injection of the polian vesicle shows that it forms one continuous tube system with the circular canal and its sinuses, oval sinuses and tentacles, ampullæ and pedicels. Unless the pressure is kept up for a considerable time there is no penetration of the injected fluid into the stone canal, and either the ring, the vesicle, or a sinus gives way before the fluid reaches the madreporic plate. Specimens injected with a gelatine mass show that each canal sinus opens into a cæcal tube, which runs forwards internal to the sinuses of the tentacles as far as a wide circum-oral space. This space communicates by well-defined apertures with that portion of the body cavity which lies between the sinuses and the œsophagus, and which is reached through the circular apertures between the sinuses of the circular canal. Each canal sinus has three other apertures in its walls. It opens by a small round aperture into a radial canal, and the two other apertures occur as minute slits, one at each side of the orifice of the radial canal leading into the adjacent tentacle sinuses. When the tentacle into which the sinus opens is protruded, there is no constriction between the sinus and the tentacle ; but when the ten­tacle is retracted, there is a well-marked constriction at the junction of the sinus with the tentacle. The eversion of the perisome and the protrusion of the tentacles are effected chiefly by the shortening of the polian vesicle and the constriction of the longitudinal muscular bands, which run from the inner surface of the body wall between each two adjacent tentacle-sinuses ; but the circular fibres of the body wall also assist in the process by contracting immediately behind the group of sinuses, so as to act on them by direct pressure, and also indirectly by forcing the body fluid against them.

Memoirs: The Atrium and the Prostate Gland in the Microdrili

1925 ◽  
Vol s2-69 (275) ◽  
pp. 399-444
Author(s):  
H. R. MEHRA
Keyword(s):  
Vas Deferens ◽  
Prostate Gland ◽  
Ventral Side ◽  
Tubifex Tubifex ◽  
Muscle Fibres ◽  
Atrial Wall ◽  
Sperm Duct ◽  
Prostate Cells ◽  
Glandular Cells ◽  
Secretory Products

1. The atrium in two species of the Naididae is described. The prostate in Nais elinguis forms the wall of the vas deferens; in Slavina punjabensis it covers the atrium. The atrium is formed as an ectodermal invagination and always occupies a position at the end of a short vas deferens. The atrial epitbehium in the sexually mature Stylaria lacustris and Slavina punjabensis is replaced by the prostatic secretion which passes through it ; it is not really composed of glandular cells as has been so far considered. 2. The prostate cells in the Naididae may surround the atrium or the vas deferens or both. The cells appear to penetrate into the muscle-fibres of the atrial wall in order to directly communicate with the atrial epithelium. They also become more or less completely changed in the late stage of sexual maturity into the secretion and lose their identity. The prostate cells are peritoneal in origin. The prostate may be absent or rudimentary in some species of the Naididae. 3. Various stages in the development of the sperm-duct in Tubifex barbatus are described. The atrium is shown to be a part of the vas deferens and hence mesodermal in origin. The prostate lies near the seminal funnel on the ventral side of the vas deferens just above the ovary ; in the early condition it is a deeply stained mass of nuclei with a little cytoplasm and continuous with the peritoneal layer of the vas deferens in front and behind. 4. The atrium and the prostate in Tubifex tubifex and Limnodrilus udekemianus are described. The prostate is peculiar in the species of the Tubificidae iuvestigated in the fact that the secretion of a fibrillar appearance forms the centre of the gland, while the cells occupy the periphery. The fibrillar secretion flows into the atrial epithelium, through a regular passage or opening where the muscular wall is absent. This appearance probably led previous workers to suppose that the prostate cells open by long ductules at the point of communication with the atrium. There is no evidence whatsoever that the prostate arises as an outgrowth from the atrial epithelium ; on the other hand it is obviously peritoneal in origin. 5. The cytoplasm in the prostate cells is basophil as distinguished from the acidophil central part with the secretion, and in Tubifex tubifex during the advanced condition of the gland generally contains basophilous granules, which pass with the fibrillar secretion as secretory products into the atrium. The prostate cells in the advanced sexual condition lose their structure and do not show mitochondria. 6. The atrial epithehium in all the Species of the Tubificidae considered is not composed of gland-cells. It is on account of the prostatic secretion, which passes through it into the atrial lumen, that it degenerates and its cells break down. 7. The prostatic secretion in the Naididae and Tubificidae appears as a fluid of thick consistency. Its function is mainly to cement or unite sperms received in the atrium. It does not contain mucin, but in sections of Tubifex tubifex prepared according to the Mann-Kopsch method the central conducting part of the gland and a portion of the atrial wall show the presence of a large amount of fat, mainly olein, or some lipoid substance, which reduces osmium tetroxide, and thus becomes deep black like the dictyosumes of the Golgi apparatus. 8. The homologies of the atrium and the prostate are briefly discussed in the various families of the Microdrili. 9. Peculiar features in the structure of the vas deferens in Tubifex tubifex and Limnodrilus udekemianus are described.

The bionomics and parasitic development of Tripius sciarae (Bovien) (Sphaerulariidae: Aphelenchoidea), a nematode parasite of sciarid flies (Sciaridae: Diptera)

Parasitology ◽  
1965 ◽  
Vol 55 (3) ◽  
pp. 559-569 ◽  
Author(s):  
George O. Poinar
Keyword(s):  
Adult Female ◽  
Body Wall ◽  
Pupal Stage ◽  
Body Cavity ◽  
The Body ◽  
National Institutes Of Health ◽  
New Host ◽  
Experimental Station ◽  
Rothamsted Experimental Station ◽  
Fat Bodies

After penetrating through the body wall into the haemocoel of Bradysia paupera, the fertilized female of Tipius sciarae increased in size and slowly expelled the enlarging uterine cells through the vulva.Within 7 days of penetration, the females were mature and began laying eggs into the haemocoel of the host. The eggs hatched in 3 days and, within 2 weeks, the host–s body was swarming with juvenile nematodes. The juveniles moulted three times in the body cavity of the host and 4th-stage forms emerged through ruptures in the intestine or body wall (in larval hosts) or were deposited on the surface of the soil (by adult female flies). They then moulted to adult forms while remaining ensheathed in their last juvenile cuticle, mated, and the fertilized infective females were ready to enter a new host.Most parasitized fly larvae died before reaching the pupal stage but some emerged as adults, still carrying the nematodes within them. All parasitized adult flies were sterile. Infested larvae had smaller fat bodies and adult histoblasts than normal larvae and took twice as long to develop.Preliminary tests suggested that this nematode may be useful in controlling sciarid gnats in glasshouses.T. sciarae (Bovien) and T. gibbosus (Leuckart) were compared.This work was done at Rothamsted Experimental Station, Harpenden, Herts, England, while the author held a postdoctoral grant from the National Institutes of Health, Bethesda, Maryland. I thank Mr F. G. W. Jones for a place in the Nematology Department, Dr Audrey Shepherd for supplying the New Blue R stain, Dr J. B. Goodey for advice, and Dr K. Lindhardt, Denmark, for the loaning of the late Dr Bovien–s slides of T. sciarae.

Functional bursting by the dracunculoid nematode Philonema oncorhynchi

Parasitology ◽  
1974 ◽  
Vol 69 (3) ◽  
pp. 417-427 ◽  
Author(s):  
J. W. Lewis ◽  
D. R. Jones ◽  
J. R. Adams
Keyword(s):  
Sodium Chloride ◽  
Hydrostatic Pressure ◽  
Sockeye Salmon ◽  
Body Wall ◽  
Body Cavity ◽  
The Body ◽  
Absolute Pressure ◽  
Unit Surface Area ◽  
Ionic Exchange ◽  
Rate Of Increase

Using biomedical techniques experimental determinations of the hydrostatic pressure in the pseudocoel of adult female Philonema oncorhynchi indicated that the rate of increase in pressure (dP/dT) and absolute pressure values (cm/H2O) shown by bursting worms in distilled water are correlated with the diameter of the nematode. At bursting pressures, wall tension in a wide size range of worms was virtually identical, indicating that the bursting process is independent of muscular contraction. That the generation of the hydrostatic pressure was an osmotic phenomenon was confirmed by measuring dP/dT in prelarvigerous and larvigerous female worms subjected to different concentrations of sodium chloride, ranging from 89 to 800 m-osmol/kg, and also to a variety of solutions of similar osmolarity (155–175 m-osmol/kg), e.g. magnesium sulphate, urea, potassium chloride, sodium chloride and sucrose. The overall rate of uptake was faster in the larger worms but, per unit surface area, small worms had an uptake rate three times that of the large individuals.The prediction that the body wall of female P. oncorhynchi is permeable to ions such as Na+ was confirmed using radiolabelled 22Na and by bringing about changes in the osmolarity of worms subjected, for 5 min periods, to hyperosmotic solutions of sodium chloride and sucrose. The survival of P. oncorhynchi in the body cavity of sockeye salmon, Oncorhynchus nerka, is dependent upon the permeable nature of the body wall of P. oncorhynchi allowing the worm to function as an ‘osmometer', because as the anadromous O. nerka enters fresh water, the osmolarity of its blood plasma is known to decrease by about 15%. At the time of spawning in Cultus Lake, British Columbia, the body fluids of both female P. oncorhynchi and O. nerka are isosmotic, indicating that the worms are able to equilibrate to the above changes and at the same time preventing premature bursting in the body cavity of its host. However, osmotic invasion of water must occur far quicker than ionic exchange since complete release of larvae does take place when female worms pass out into the redd along with the eggs of the fish and burst.

Evolutionary Waves: Patterns in the Origins of Animal Phyla.

1985 ◽  
Vol 33 (2) ◽  
pp. 153 ◽  
Author(s):  
WG Inglis
Keyword(s):  
Body Wall ◽  
Functional Anatomy ◽  
Distinct Group ◽  
Body Cavity ◽  
The Body ◽  
Animal Groups ◽  
Structural Modifications ◽  
Hydrostatic Skeleton ◽  
Animal Phyla ◽  
Common Ancestors

Concordant patterns of embryology, morphology and functional anatomy delimit grades of animal phyla, each of which contains a 'Major Phylum': PARACOELOMATA (nom.nov.) = acoelomates + pseudocoelomates, flexible hydrostatic skeleton, Nematoda; DEUTEROSTOMIA (including lophophorates) = enterocoelic coelom, rigid internal skeleton, Chordata; and PROTOSTOMIA with two subgrades, MONOMERIC P. = unsegmented, single coelom, molluscan blastular cross, partial rigid exoskeleton, Molluscs; and POLYMERIC P. = segmented, multiple coelom, annelid cross, rigid exoskeleton, Uniramia. Such groups are usually treated as arbitrary stages in mono- and limited-branch phylogenies, but recent studies show them to be real and significant because the only phylogenetic links are from each Paracoelomata and Protostomia Phylum to Turbellaria; and each Deuterostomia Phylum to Cnidaria-Ctenophora and/or enteropneust Hemichordata. Similar grades have often been explained by hypothetical common ancestors, which are unnecessary if the phyla arose during 'evolutionary waves'. These attribute the origin of each grade to the likelihood that its constituent phyla arose independently, about the same time, from the same ciliary powered ancestral stock which was preadapted to enabling a potential body cavity to be actualized while evolving a cylindrical, wholly muscle-powered, body with a hydrostatic skeleton. Because such a skeleton is functionally dependent upon other structural modifications, particularly of the body wall, it could appear only when these were also available. If the latter could be supplied in a number of ways, all opportunities would be exploited and a body cavity would appear several times. The morphology suggests that this did happen, so that a pseudocoelom and coelom evolved independently in each phylum where they occur. Because of evidence that Protostomia and Deuterostomia were never linked during evolution, the origin of the coeloms in the former are explained by the Gonocoelic Theory and in the latter by the Enterocoelic. This, with the recognition of the monomeric protostomes as a distinct group, establishes that segmentation arose at the same time as the coeloms, so that their origins are one problem and not two as usually thought. Finally, protistan data suggest that Turbellaria, and so Paracoelomata and Protostomia, arose from 'close mitosis' flagellates, as did Fungi; while Cnidaria, and so Deuterostomia, arose from 'open mitosis' flagellates. as did Plantae. Thus, the classic Animalia division into Protostomia and Deuterostomia may represent a Protista division such that the animal groups are closer to fungi and plants respectively than they are to each other.

scholarly journals Reproductive system morphology of giant barnacle “picoroco” Austromegabalanus psittacus (Molina, 1782) (Cirripedia, Balanidae)

2017 ◽  
Vol 43 (3) ◽  
pp. 607-615
Author(s):  
Catalina Contreras ◽  
Nicolás Luna ◽  
Enrique Dupré
Keyword(s):  
Reproductive System ◽  
Ejaculatory Duct ◽  
Mature Oocyte ◽  
Body Cavity ◽  
The Body ◽  
Thick Wall ◽  
Main Body ◽  
Simultaneous Hermaphrodite ◽  
Internal Wall ◽  
Reproductive Structures

The reproductive structures of Austromegabalanus psittacus in two periods of sexual maturation were described. This organism is a simultaneous hermaphrodite, which transfers his sperm through an intromittent organ or penis. The male reproductive system consists of testes arranged in acini distributed in a tree-like structure, two vasa deferentia that come together to form the ejaculatory duct at the base of the penis. The female reproductive system consists mainly of a saccular ovary that surrounds the main body, which is internally organized into elongated acini bags containing oogonia and previtellogenic oocytes attached to the internal wall and free vitellogenic and mature oocyte within the lumen. Remarkable differences were observed in the ovaries between organisms collected in September and October. In September, they showed a yellowish ovary with two compact structures inside, called ovigerous lamellae with fertilized oocytes, embryos in different development stages and free nauplius in the body cavity, whereas in October the ovaries have a whitish in color and present a thick wall with a milky fluid inside.

III. On the structure and development of Lepidosteus

1882 ◽  
Vol 33 (216-219) ◽  
pp. 112-119 ◽  
Keyword(s):  
Outer Zone ◽  
Body Cavity ◽  
The Body ◽  
Yolk Mass ◽  
Larval Life ◽  
General Development ◽  
History Of ◽  
Optic Vesicles ◽  
The Brain ◽  
Olfactory Pit

The authors commence this paper by thanking Professor Alexander Agassiz for the material, both embryological and adult, on which these researches were made. The first section is devoted to the general development. In this section an account is given of the structure of the ripe ovum, of the segmentation, of the history of the germinal layers, of the first development of the principal organs, and of the external features of the embryo during embryonic and larval life. The more important points established in this section, are— (1.) The ovum when laid is invested by a double covering formed of ( a ) a thick inner membrane, the outer zone of which is radially striated, and ( b ) an outer layer made up of highly refractive pyriform bodies which are probably metamorphosed follicular epithelial cells (2.) The segmentation is complete, though very unequal; the lower pole being very slightly divided into segments, and its constituent parts subsequently fusing together to form an unsegmented mass of yolk, like the yolk-mass of Teleostei. (3.) The epiblast is divided into an epidermic and a nervous stratum , as in Teleostei. (4.) The walls of the brain, of the spinal cord, and of the optic vesicles are formed from a solid medullary keel, like that found in Teleostei. (5.) The lens, the auditory vesicle, and the olfactory pit, are wholly developed from the nervous layer of the epidermis. (6.) The segmental or archinephric duct is developed, as in Teleostei, from a hollow ridge of the somatic mesoblast, which becomes constricted off, except in front; thus forming a duct with an anterior pore leading into the body cavity.

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