VI.—A Contribution to the Life-History of Bowenia

1926 ◽  
Vol 54 (2) ◽  
pp. 357-394 ◽  
Author(s):  
A. Anstruther Lawson
Keyword(s):  
Life History ◽  
Geographical Distribution ◽  
Great Powers ◽  
Land Plants ◽  
Long Period ◽  
Wide Geographical Distribution ◽  
The Earth ◽  
History Of

The existing Cycads, with their nine genera and about eighty known species, represent the last lingering survivors of an ancient race that existed in Mesozoic times. There is very little evidence of their geological and geographical distribution throughout that great period; but it seems that up to the close of the Cretaceous they constituted an important feature of the Land Vegetation, with the Bennettitales, Ginkgoales, and Coniferales as their contemporaries. During that long period they were probably represented by many genera and species, and apparently enjoyed a very wide geographical distribution. The nature of their seed as an organ of reproduction seems to have endowed them with great powers of propagation and dissemination, which enabled them to spread over the earth and to occupy dry soils which probably had never before been occupied by Land Plants.

II. Note on Professor Hull’s paper

1887 ◽  
Vol 42 (251-257) ◽  
pp. 308-310
Keyword(s):  
Life History ◽  
Sea Water ◽  
Chemical Change ◽  
The Earth ◽  
Organic Body ◽  
History Of

Dr. Alleyne Nicholson, a palæontologist of no small repute, refers to this subject in his work on the ‘ Ancient Life History of the Earth,’ p. 34. He considers that the silica which has surrounded and infiltrated the fossils which flint contains, must have been deposited “from sea-water in a gelatinous condition, and subsequently have hardened.” Also that “the formation of flint may therefore be regarded as due to the separation of silica from sea-water, and its deposition round some organic body in a state of chemical change or decay.”

Henry Nicholas Ridley, 1855-1956

1957 ◽  
Vol 3 ◽  
pp. 141-159 ◽  
Keyword(s):  
Plant Physiology ◽  
Life History ◽  
Geographical Distribution ◽  
Botanic Gardens ◽  
Intellectual Activity ◽  
Sexual Process ◽  
History Of ◽  
Personal Qualities ◽  
The Individual ◽  
Seeds And Fruits

When anyone attains to over a century at the time of their death it is inevitable that there should be few, even of near contemporaries, who can attest to the personal qualities that marked the individual in the full vigour of his career, but this deficiency is less marked with respect to H. N. Ridley, since he retained so much of his vigour and particularly his mental zest until almost the closing years of his life and, moreover, he fortunately left a personal record that has been invaluable in reconstructing the beginnings of his career. The writer is also indebted to his widow and to Mr I. H. Burkill, who succeeded Ridley as Director of the Botanic Gardens, Straits Settlements, from 1912 to 1925, for help in relation to the earlier years. Henry Nicholas Ridley was born on 10 December 1855 at the period when plant physiology under the influence of Dutrochet, Leibig and Boussingault was beginning to affect the general approach to the study of plants, and when Hofmeister had conclusively shown the nature of the sexual process in phanerogams and had given an impetus to the study of the life history of plants. Thus Ridley grew up in a period of great intellectual activity but, above all, in its influence on the young men—the Origin of Species appeared when he was four years old. By the time Ridley was a student this had become a vitalizing influence in botanical thought and outlook, which gave a new significance to the study of modes of dispersal of seeds and fruits and to the geographical distribution of plants, that had a lifelong effect on Ridley’s concepts and interests.

scholarly journals Life in the Slow Lane: Reproductive Life History of the White-Browed Scrubwren, an Australian Endemic

The Auk ◽  
2000 ◽  
Vol 117 (2) ◽  
pp. 479-489 ◽  
Author(s):  
Robert D. Magrath ◽  
Ashley W. Leedman ◽  
Janet L. Gardner ◽  
Anthony Giannasca ◽  
Anjeli C. Nathan ◽  
...  
Keyword(s):  
Life History ◽  
Life Histories ◽  
Life History Traits ◽  
Life History Strategy ◽  
Breeding Biology ◽  
Long Period ◽  
Successful Attempt ◽  
Reproductive Life ◽  
History Of ◽  
Small Clutch

Abstract An understanding of geographic and phylogenetic variation in passerine life histories is hampered by the scarcity of studies from the Southern Hemisphere. We documented the breeding biology of the White-browed Scrubwren (Sericornis frontalis), an Australia endemic in the Pardalotidae (parvorder Corvida). Like other members of the Pardalotidae, scrubwrens had a long laying interval (two days), a long incubation period (declining from 21 to 17 days through the season), and a long period of postfledging parental care (6 to 7 weeks). Scrubwrens appeared to be typical of the Australian Corvida in having a small clutch size (three eggs) and a long breeding season (5.4 months), and they also had a long interval between breeding attempts (10 days after a failed attempt, 21 days after a successful attempt). Scrubwrens were multibrooded, often raising two broods successfully and occasionally raising three broods. The breeding biology of scrubwrens adds further support to claims of a distinct life-history strategy for members of the Corvida but also reinforces evidence that some “Corvida” life-history traits more specifically are those of the Pardalotidae.

scholarly journals I.—American “Surface Geology,” and its Relation to British. With some Remarks on the Glacial Conditions in Britain, especially in Reference to the “Great Ice Age” of Mr. James Geikie

1877 ◽  
Vol 4 (11) ◽  
pp. 481-496
Author(s):  
Searles V. Wood
Keyword(s):  
United States ◽  
Life History ◽  
North America ◽  
The United States ◽  
Ice Age ◽  
The Earth ◽  
The World ◽  
History Of ◽  
The Rich ◽  
Surface Geology

From no part of the world have we of late years derived more additions to the Geological Record than from North America. Besides important additions to the earliest pages of that record, the rich collections made by the United States Surveyors, both of fauna and flora, from the Cretaceous, Eocene, and Miocene deposits, have thrown much light upon the life history of the Earth; and it is even contended that they have bridged over the interval which, notwithstanding the Maestricht beds, the Pisolitic, and the Faxoe Limestones, still remains sharply marked between the Cretaceous and Tertiary formations of Europe so far as they have yet been examined.

scholarly journals LIFE-HISTORY OF LYDA FASCIATA (NORTON), FAM. TENTHREDINIDÆ

1902 ◽  
Vol 34 (8) ◽  
pp. 214-216
Author(s):  
Richard. F. Pearsall
Keyword(s):  
Life History ◽  
Coming Out ◽  
Wild Cherry ◽  
The Earth ◽  
History Of ◽  
Deep Green

Full-grown larvæ were taken on wild cherry (Prunus) in the latter part of September, 1901. Placed in a box over earth, they fed but a day or two, truned a deep green, and entering the earth two to three inches, formed rounded cells, in which they remained as larvæ all winter, transforming to pupæ just before emergence. They are gregarious, remaining in their web, filled with its mass of exuvia, untill full-grown, when, as their growth is completed, individually they drop from it and enter the ground. One which was kept under observation formed a pupa on April 28th, and emerged eight days thereafter. The pupal skin is very thin, showing distictly the parts of the enclosed imago. This brood commenced emerging April 25th, and a few individuals are still coming out, May 31st. In the eariler days the males predominated, later the females, Altogether, 134 males and 123 females have appeared. Copulation took place at once, the pair remaining in coitu from three to five hours.

scholarly journals Women in Early Human Cytogenetics: An Essay on a Gendered History of Chromosome Imaging

2020 ◽  
Vol 28 (2) ◽  
pp. 170-200
Author(s):  
María Jesús Santesmases
Keyword(s):  
Clinical Practice ◽  
Geographical Distribution ◽  
Genetic Diagnosis ◽  
Historical Reconstruction ◽  
Wide Geographical Distribution ◽  
Laboratory Bench ◽  
Human Cytogenetics ◽  
History Of ◽  
Biological Concepts ◽  
Early Human

Alongside the renowned male pioneers of medical cytogenetics, many women participated in investigations at the laboratory bench and the bedside, both in Europe and the Americas. These women were committed to this new biological and clinical practice—cytogenetics, the origins of contemporary genetic diagnosis—and contributed to the creation of new biological concepts and settings centered on the study of chromosome imaging. This paper will review the contributions made by a group of woman scientists from a wide geographical distribution, situating their names and research agendas within the history of a field dating back to early plant and insect cytogenetics. Rather than an exhaustive compendium of women geneticists, this essay presents a kind of historical reconstruction that can be achieved by placing women at center stage in their geographies and networks of circulating cytogenetic knowledge and practices thereby relating a history of genetic images though the work carried out by women, retrieving their agency and constructing an inclusive history of an influential contemporary biomedical practice as it gained increasing influence in the laboratory and the clinic.

The Trematode Parasites of Irish Marine Fishes

Parasitology ◽  
1929 ◽  
Vol 21 (1-2) ◽  
pp. 22-30 ◽  
Author(s):  
Percy A. Little
Keyword(s):  
Geographical Distribution ◽  
Stomach Contents ◽  
Marine Fishes ◽  
Sea Bream ◽  
Larval Stages ◽  
Wide Geographical Distribution ◽  
Grey Gurnard ◽  
History Of ◽  
The Moment ◽  
Conger Eel

A main feature of the data here presented is the number of new records. For the sake of brevity these are tabulated below, under their respective headings.Another feature is the wide geographical distribution of a large percentage of the parasites herein recorded, particularly of such forms as Zoogonoides viviparus (Olsson), Derogenes varicus (Mueller) and Hemiurus communis Odhn. The former has been recorded for St Andrews, Millport, Aberdeen, Plymouth, Northumberland, Liverpool, Galway, and also for foreign seas. Derogenes varicus has been recorded for St Andrews, Millport, Plymouth, Aberdeen, Northumberland, Galway, and for foreign seas. Hemiurus communis has been recorded for St Andrews, Millport, Plymouth, Northumberland, Liverpool, Aberdeen, Galway, and for foreign seas.This suggests that the intermediate host of the larval stages of these parasites must be some common marine form, in all probability an invertebrate, which itself enjoys a very wide geographical distribution.A further feature is the tendency of certain parasites to infect a variety of fish, the more notorious being Derogenes varicus (Mueller) and Hemiurus communis Odhn. Of the twenty-six species of marine fishes examined at Galway, eleven (42 per cent.) were found to harbour Derogenes various. The infected fishes were the bib (G. luscus), cod (G. morrhua), pollack (G. pollachius), dab (Pleuronectes limanda), plaice (P. platessa), tub (Trigla hirundo), grey gurnard (T. gurnardus), brill (Rhombus laevis), hake (Merluccius vulgaris), common sole (Solea vulgaris), common sea bream (Sparus centrodontus).Hemiurus communis was found parasitising eight species of fish, i.e. 31 per cent, of the total number of species examined. The hosts affected were the bib (G. luscus), whiting (G. merlangus), cod (G. morrhua), pollack (G. pollachius), flounder (P. flesus), tub (T. hirundo), plaice (P. platessa), and the common sea bream (S. centrodontus).At the moment it is a little premature to prophesy to what extent the discovery of encysted specimens of Prosorhynchus crucibulum (Rud.) in the gill tissues of the cod (Gadus morrhua) will assist in elucidating the life-history of this parasite. Mature specimens of Prosorhynchus crucibulum have previously been recorded as occurring in the alimentary canal of the conger eel (Conger niger). The writer discovered partly digested specimens of small cod to form a considerable bulk of the stomach contents of the conger eel.

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