II. On the organisation of the fossil plants of the coal-measures.—Part XIV. The true fructification of calamites

The systematic affinities of the Carboniferous Calamites have now been a moot question for close upon fifty years—the period that has elapsed since 1828, when, in his ‘ Prodrome d’une Histoire des Végétaux Fossiles,' Adolphe Brongniart first suggested their relationships to the recent Equisetums. At this time nothing was known of examples of Calamites encased in a thick vascular cylinder; a product of the exogenous mode of growth resulting from the action of a cambial ring. At a later period Brongniart obtained such examples from Autun and elsewhere. But having then a conviction that no Cryptogamic stem could undergo an exogenous development, he concluded that two classes of plants had been comprehended in the genus Calamites ; the one Equisetiform, to which he continued to give the old name, the other a Gymnospermous type, to which he assigned the name of Calamodendron . His well-merited influence led to a wide-spread acceptance of these views; but their correctness began to be seriously questioned many years ago, on morphological grounds. After a prolonged conflict the conclusions of those who insisted upon the Cryptogamic character alike of Calamites and of Calamodendron have met with an extensive, though not universal, acceptance. Meanwhile both the opposing schools of Palæontologists recognise the importance of discovering the fructification of these plants. Mr. Carruthers believed that he had found it in examples of Calamostachys Binneyana , and Mr. Binney arrived at a similar conclusion. I have always rejected these conclusions, because of the conspicuous differences between the morphology of the Calamitean twig and that of the axis of the Calamostachys . These differences appeared to me much too great to make it possible for the one ever to have been a prolongation of the other.

On the structure and affinities of fossil plants from the palæozoic rocks.—V. On a new type of Sphenophyllaceous cone ( Sphenophyllum fertile ) from the lower coal-measures.

10.1098/rspl.1904.0116 ◽

1905 ◽

Vol 74 (497-506) ◽

pp. 314-315

Author(s):

Dukinfield Henry Scott

Keyword(s):

The Other ◽

Fossil Plants ◽

New Type ◽

The One ◽

The class Sphenophyllales, of which the fossil described is a new representative, shows on the one hand clear affinities with the Equisetales, while on the other it approaches the Lycopods; some botanists have endeavoured to trace a relation to the Ferns. The nearest allies among recent plants are probably the Psilotaceæ, which some writers have even proposed to include in the Sphenophyllales.

XVIII. On the organization of the fossil plants of the coal-measures.—Part I. Catamites

Philosophical Transactions of the Royal Society of London ◽

10.1098/rstl.1871.0019 ◽

1871 ◽

Vol 161 ◽

pp. 477-510 ◽

Cited By ~ 10

Keyword(s):

De Novo ◽

The Other ◽

Fossil Flora ◽

Fossil Plants ◽

True Nature ◽

Inverted Position ◽

The Subject ◽

The Common ◽

The One ◽

A few preliminary words may he necessary to prevent misunderstanding respecting the claims and objects of the following memoir. When I entered upon the investigation of which it records the results, I found, in the writings of various British and foreign authors, a copious Calamitean literature; hut the widest discrepancies prevailed amongst them both as to facts and to inductions. I therefore determined to pursue the study of this group of fossils as if de novo, to record the facts which I observed, and to draw from those facts alone such inferences as seemed legitimate, both facts and inferences being in a certain sense, and so far as was possible under the circumstances, new and original. But it necessarily follows that some of these facts and inferences are not absolutely new, though many of them, I think, will he found to he additions to our knowledge of the subject; whilst others, though not new, have presented themselves to me in a light different to that in which they have been regarded by my able predecessors in the study. Such being the object of the memoir, I have not deemed it desirable to include in it a record of all the observations made by preceding writers. As a rule I have only referred to them when the discussion of some moot point rendered such a reference necessary. The fundamental aim of the memoir is to demonstrate the unity of type existing amongst the British Calamites. Brongniart, Dawson, and other writers believe that there exist amongst these plants two types of structure, the one Cryptogamic and Equisetaceous, the other Exogenous and Gymnospermous; on the other hand, Schimper and Carruthers regard the whole as Equiseceous, affording an example of the diversity of opinion on fundamental points to which I have already referred. Of course, before arriving at their conclusions, Brongniart, and those who adopt his views, had fully apprehended the exogenous structure of the woody zone of the Calamite, which is further illustrated in this memoir. The separation of each internode into vertical radiating plates of vascular and cellular tissues, arranged alternately, was familiar to Brongniart, Unger, and other early observers. Cotta regarded the cellular tracts (my primary medullary rays) as medullary rays ; but this interpretation was rejected by Unger, and the same divergence of view on this point has recurred amongst subsequent writers. Unger also noticed what I have designated secondary medullary rays, but at a much more recent date Mr. Carruthers disputed their existence. In their 'Fossil Flora of Great Britain,' Lindley and Hutton gave very correct illustrations of the position of the roots of Calamites relatively to the stem ; and yet for years afterwards some of their figures reappeared in geological text-books in an inverted position, the roots doing duty as leaves ; so far was even this elementary point from being settled. The true nature of the common sandstone form of Calamites, viz. that they are inorganic casts of the interior of the woody cylinder from which the pith has been removed, has been alike recognized by Germar, Corda, and Dawes; but they referred the disappearance of the cellular tissues of the pith to inorganic decay which took place subsequently to the death of the plant. It appears to me that the condition in which we find these cellular tissues affords no countenance to this conclusion. They are as perfectly preserved, when present, as any of the other tissues of the plant. Their inner surface, nearest the fistular cavity, presents no appearance of death and decay, but of rupture and absorption, which I conclude has occurred during life,—a different hypothesis from that adopted by my predecessors, and for which my reasons will be assigned in the memoir. The labours of Mr. Binney are referred to in the text. He figured the longitudinal internodal canals, but was disposed to believe that they had merely formed passages for vessels. He gave, however, excellent figures of the woody wedges, the primary medullary rays, and the cellular medulla, with its nodal septa or diaphragms .

XI. On the organization of the fossil plants of the Coal-measures. —Part V. Asterophyllites

10.1098/rspl.1872.0080 ◽

1873 ◽

Vol 21 (139-147) ◽

pp. 394-398 ◽

Cited By ~ 1

Keyword(s):

Royal Society ◽

The Other ◽

Fossil Plants ◽

Directed Attention ◽

Detailed Exposition ◽

Primary Type ◽

On two occasions the author directed attention, in the Proceedings of the Royal Society (vol. xx. pp. 95 & 435), to the structure of some stems which appeared to him to belong to the well-known genus Asterophyllites , briefly pointing out at the same time their apparent relations to a strobilus of which he had previously published figures and description (Transactions of the Literary and Philosophical Society of Manchester, third series, vol. v. 1871) under the name of Volkmannia Dawsoni . In the present memoir he gives a detailed exposition of the various parts of the plant, including the roots, rootlets, stems, branches, leaves, and fruit, in different stages of their development. This is done chiefly in two modifications of the primary type—one from the Lower Coal-measures Oldham in Lancashire, the other from those of Burntisland.

On the structure and affinities of fossil plants from the palæozoic rocks. II. On spencerites , a new genus of lycopodiaceous cones from the coal-measures, founded on the lepidodendron spenceri of Williamson

10.1098/rspl.1897.0089 ◽

1898 ◽

Vol 62 (379-387) ◽

pp. 166-168 ◽

Cited By ~ 2

Keyword(s):

New Genus ◽

The Other ◽

Fossil Plants ◽

The Subject ◽

The fossils which form the subject of the present paper are Cryptogamic strobili, showing evident Lycopodiaceous affinities, but differing in important points from other fructifications of that family, so that it appears necessary to establish a new genus for their reception. Two species are described, one of which ( Spencerites insignis ) is already known to us from the investigations of Williamson, who named it first Lepidostrobus insignis , and afterwards Lepidodendron Spenceri while the other ( Spencerites majusculus ) is new.

XIII. On the organization of the fossil plants of the coal-measures. —Part III. Lycopodiaceæ (continued)

Philosophical Transactions of the Royal Society of London ◽

10.1098/rstl.1872.0013 ◽

1872 ◽

Vol 162 ◽

pp. 283-318 ◽

Cited By ~ 12

Keyword(s):

Royal Society ◽

New Genus ◽

The Other ◽

Raw Material ◽

Fossil Plants ◽

Extended Study ◽

Other Hand ◽

The Subject ◽

Coal Measures ◽

The Relationship

In the last memoir which I laid before the Royal Society I described a number of forms of Lepidodendroid plants from the Coal-measures, without making any material attempt to ascertain the relationship which they bore to each other. I now propose to carry the subject somewhat further, and to show that some of these apparently varied forms of Lycopodiaceæ merely represent identical or closely allied plants in different stages of their growth. The discovery of some remarkable beds in Burntisland, by George Grieve, Esq., and his persistent kindness in supplying me abundantly with the raw material upon which I could work, have enabled me to do this in a manner, at least, satisfactory to myself. Upon the geology of these remarkable beds I will not now enter, beyond saying that they appear to have been patches of peat belonging to the lower Burdiehouse series, which are now imbedded in masses of volcanic amygdaloid. The stratum, where unaltered by contact with the lava, is little more than a mass of vegetable fragments, the minute structure of most of which is exquisitely preserved. The more perfect remains that are capable of being identified belong to but few types. The most abundant of these are the young twigs of a Lepidodendron , portions of the stem of a Diploxylon , stems of a remarkable Lycopodiaceous plant belonging to my new genus Dictyoxylon (but which, for reasons to be stated in a future memoir, I propose to unite with Corda’s genus Heterangium , under the name of H. Grievii ), and fragments of Stigmaria-ficoides . Along with these occur, but more rarely, several other curious Lycopodiaceous and Fern stems, and those of an articulated plant, which I believe to be an Asterophyllites ; also some true Lepidostrobous fruits and myriads of caudate macrospores belonging to the Lepidostrobi . The first point to be noted is that all the Lepidodendroid branches are young twigs. No one example of a large stem has been found presenting exactly the same structure as these small branches, which, as already stated, are so abundant. On the other hand, all the Diploxylons are large branches or matured stems. These facts at once suggested the inquiry whether the two plants referred to might not be complementary to each other. A careful and very extended study of a large number of specimens has convinced me that such is the case. I have made more than a hundred sections of the two forms, and the result has been a remarkably clear testimony that the Lepidodendra are the twigs and young branches of the Diploxylon -stems. I am also led to the conclusion that the Lepidostrbi , with their peculiar macrospores and microspores, belong to the same plant. I will examine each of these forms in detail.

II. On the organization of the fossil plants of the coal-measures.—Part III. Lycopodiaceæ

10.1098/rspl.1871.0047 ◽

1872 ◽

Vol 20 (130-138) ◽

pp. 199-203

Keyword(s):

Cellular Tissue ◽

Igneous Rocks ◽

Single Bundle ◽

Epidermal Layer ◽

Vascular Cylinder ◽

Fossil Plants ◽

Similar Series ◽

The Subject ◽

Short Time ◽

An outline of the subject of this memoir has already been published in the Proceedings in a letter to Dr. Sharpey. In a former memoir the author described the structure of a series of Lepidodendroid stems, apparently belonging to different genera and species. He now describes a very similar series, but all of which, there is strong reason for believing, belong to the same plant, of which the structure has varied at different stages of its growth. The specimens were obtained from some thin fossiliferous deposits discovered by Mr. G. Grieve of Burntisland, in Fifeshire, where they occur imbedded in Igneous rocks. The examples vary from the very youngest, half-developed twigs, not more than 1/12 of an inch in diameter to arborescent stems having a circumference of from two to three feet. The youngest twigs are composed of ordinary parenchyma, and the imperfectly developed leaves which clothe them externally have the same structure. In the interior of the twig there is a single bundle, consisting of a limited number of barred vessels. In the centre of the bundle there can always be detected a small amount of primitive cellular tissue, which is a rudimentary pith. As the twig expanded into a branch, this central pith enlarged by multiplication of its cells, and the vascular bundle in like manner increased in size through a corresponding increase in the number of its vessels. The latter structure thus became converted into the vascular cylinder, so common amongst Lepidodendroid plants, in transverse sections of which the vessels do not appear arranged in radiating series. Simultaneously with these changes the thick parenchymatous outer layer becomes differentiated. At first but two layers can be distinguished—a thin inner one, in which the cells have square ends, and are disposed in irregular vertical columns, and a thicker outer one consisting of parenchyma, the same as the epidermal layer of the author’s preceding memoir. In a short time a third layer was developed between these two.

XIX. On the organization of the fossil plants of the coal-measures.—Part VI. Ferns

Philosophical Transactions of the Royal Society of London ◽

10.1098/rstl.1874.0019 ◽

1874 ◽

Vol 164 ◽

pp. 675-703 ◽

Cited By ~ 10

Keyword(s):

The Other ◽

Natural Order ◽

Single Bundle ◽

Clear Indication ◽

Fossil Plants ◽

Exogenous Growth ◽

Dicotyledonous Plants ◽

Generic Groups ◽

Primary Groups ◽

In no part of the investigation upon which I have been so long engaged have I encountered so many real difficulties as in that of which I am about to lay the results before the Society. Amongst the earliest sections which I made I found anomalous structures, generally consisting of a single bundle of vessels, such bundles varying much in size and form, enclosed in a parenchymatous or prosenchymatous bark. Few of these examples exhibited any clear indication of the group of plants to which they had respectively belonged. Many of them might have been either Lycopods or Ferns, so far as structure was concerned. But in addition to the difficulty of assigning them to their respective groups, was the further one of determining which were independent plants or which merely varying portions of the same plant. This latter difficulty is more real in the case of Ferns than of Lycopods, because nothing is more common amongst the recent examples of the ferns than to find a rhizome possessing one structure, its primary petiole another, and its secondary and tertiary petioles yet different structures; consequently it became exceedingly probable that similar variations would be found in fossil types. This possibility was converted into a certainty by the researches of Cotta, Corda, and Renault, all of whom obtained stems with petioles attached, and which exhibited differences such as I have referred to. But supposing all these difficulties to have been overcome, supposing the disjecta membra of each plant to have been properly collocated, and each species to have been correctly referred to its natural order, a new difficulty arose from the plans of procedure adopted by previous writers on this subject. In 1832 C. Bernard Cotta published his ‘Dendrolithen,’ giving descriptions and somewhat defective figures of a number of specimens to which he assigned new generic and specific names. He threw these forms into the three families of Rhizomata, Stipites, and Radiati, the latter family being defined as “Caules ad tertiam familiam pertinentes strias radiales continent, quæ horizontaliter perscissæ vel inter se separatos concentricos annulos formant, vel inde ab axe incipientes usque ad peripheriam exeunt” ( loc. cit . p. 58). The plants thus defined are obviously such as I should have considered to possess some modification of exogenous growth, though Cotta points out certain features in which he considers that they differ from the stems of true Dicotyledons. The above publication was followed in 1845 by Corda’s noble work entitled “Beiträge zur Flora der Vorwelt.” In this admirably illustrated volume he described and figured a large number of hitherto unknown forms, and included in his respective genera all those previously described by Cotta, the whole being thrown into two primary groups. One of these groups was composed of what he regarded as Monocotyledonous and Dicotyledonous plants, the other of Ferns. These groups he further divided into secondary natural families. The only one of these latter belonging to his first division which concerns me now is that of the Palmæ. The Ferns he divided into seven families and more than forty genera, the latter being too often based upon the most insufficient characters. The undue multiplication of genera by this distinguished botanist was very properly objected to by M. Brongniart, who says, “M. Corda, dans son essai sur la flore de l’ancien monde, me paraît avoir trop multiplié, pour l’état actuel de nos connaissances, les genres fondés sur les tiges des Fougères, dont nous ne connaissons généralement la structure que d’une manière trop imparfaite pour établir des divisions bien définies” (‘Tableau des genres de Végétaux Fossiles,’ p. 34, 1849). He then proceeds to throw many of Corda’s genera into more comprehensive generic groups, still retaining sixteen genera, nine of which, however, he regards as merely provisional ones.

VI. On the organisation of the fossil plants of the coal-measures. Part XI

10.1098/rspl.1879.0160 ◽

1880 ◽

Vol 30 (200-205) ◽

pp. 550-554

Keyword(s):

Vascular Cylinder ◽

Fossil Plants ◽

Coal Measures ◽

Medullary Cells

M. Renault has recently published a memoir, in which he reproduces the views of M. Brongniart respecting the relations which the Lepidodendra bear to the Sigillarise, still insisting that the former are cryptogamic Lycopods, whilst the latter are exogenous Gymnosperms. In endeavouring to establish this position, the French palæo-botanist concludes that if the exogenous Diploxyloid stems ( i. e . Sigillarianones) are but matured states of some Lepidodendra, every Sigillarian type of organisation ought to be found in a young or Lepidodendroid form, because, he contends, the type of the central organisation, once established, undergoes no further change. with advancing age. In support of his position, he affirms that there are three such Sigillarian types, viz., Sigillaria vascularis; 2. Diploxyloid stems ; 3. Favularia and Leiodermaria. At present he contends that only the second of these forms has been discovered in Lepidodendron Harcourtii. He further believes that there are three types of Lepidodendron known, represented by—1. L. Rhodumense, with a solid central vascular axis, in which the vessels are not intermingled with medullary cells ; 2. by L. Harcourtii, in which the vascular axis is a cylinder surrounding a cellular medulla; and, 3. An undescribed plant, which he names L. Jutieri, in which the vascular cylinder is broken up into detached bundles of vessels.

VII. On the organization of the fossil plants of the coal-measures.―Part VIII. Ferns (continued) and gymnospermous stems and seeds

Philosophical Transactions of the Royal Society of London ◽

10.1098/rstl.1877.0007 ◽

1877 ◽

Vol 167 ◽

pp. 213-270 ◽

Cited By ~ 18

Keyword(s):

Transverse Section ◽

External Surface ◽

Cortical Layer ◽

Maximum Diameter ◽

Vascular Cylinder ◽

Fossil Plants ◽

Vascular Elements ◽

The Rich ◽

The Difference ◽

In one of his valuable Memoirs on the Fossil Plants of the Carboniferous deposits of France M. Renault has described the stems of two fossil Ferns, to both of which examples characteristic petioles are attached. In these stems the chief vascular or pseudo-vascular elements are not scattered over the transverse section of the stem in detached bundles, as is usual amongst living Ferns, but they are gathered together so as to form an axial cylinder, enclosing an irregular, central, radiating medulla composed of parenchymatous tissue. In the sixth of this series of memoirs I figured (plate 58. fig. 51) a transverse section of a similar vascular axis, but without either petioles or even any investing cortical layer attached to it. In one of M. Renault’s examples the petioles associated with the stem were identical with those to which Corda gave the name of Zygopteris . In the second species, to which M. Renault assigned Corda’s generic name of Anachoropteris , the transverse section of the petiolar vascular bundle resembles that of Osmunda and Todea , as M. Renault has correctly indicated ( loc. cit . p. 176). He also points out the difference existing between the closed vascular cylinders of the stems of these two Ferns and the corresponding bundles of most living types, but thinks that something similar to them may be found amongst the Ophioglossums . I am indebted to my indefatigable auxiliary, Mr. J. Butterworth, for an interesting stem of the same type which he obtained from the rich reservoir of fossil plants near Oldham. The specimen was about 1 1/2 inch in length, whilst its somewhat oval, transverse section had a maximum diameter of about an inch. The external surface was strongly marked by an irregular series of transverse ridges and furrows, represented in fig. 1, and which may some day contribute to the identification of the fronds with which this stem should be associated. There aye about twenty-four of these ridges, with corresponding intermediate furrows, to each vertical inch of the stem. On making a transverse section of the specimen I found a central vascular cylinder closely resembling that seen in M. Renault’s specimen of Zygopteris Brongniarti ( l. c . pl. 3. fig. 1, a ), along with two or three secondary ones, of varying dimensions, dispersed over the area of the section. Utterly unable to interpret the relations of these several structures, I adopted the plan which proved so successful in the case of Heterangium Grievii (Phil. Trans. 1873, pl. xxx. figs. 37-44), and had about an inch of the specimen cut up into the series of closely consecutive, transverse sections represented in figs. 2-12. By this process a partial interpretation of these sections, at least, has become sufficiently easy.

Autoimmune thyroiditis. - Bishkek, 1996 .-- 158 p. D. S. Rafibekov, A. P. Kalinin

Problems of Endocrinology ◽

10.14341/probl199743651-52 ◽

1997 ◽

Vol 43 (6) ◽

pp. 51-52

Author(s):

I. D. Levit

Keyword(s):

Autoimmune Thyroiditis ◽

Detection Rate ◽

The Other ◽

Wide Spread ◽

Other Hand ◽

The World ◽

The One

The monograph is dedicated to autoimmune thyroiditis (AIT), a “young” disease described 85 years ago. The problem is little developed, despite the wide spread of the disease throughout the world. Scientists and practitioners are generally new to her. Hence, on the one hand, the low detection rate of the disease, on the other hand, its overdiagnosis.