new icn messageflickr-free-ic3d pan white
Image from page 154 of "The origin and evolution of life, on the theory of action, reaction and interaction of energy" (1917) | by Internet Archive Book Images
Back to photostream

Image from page 154 of "The origin and evolution of life, on the theory of action, reaction and interaction of energy" (1917)

Identifier: originevolutiono00osbo

Title: The origin and evolution of life, on the theory of action, reaction and interaction of energy

Year: 1917 (1910s)

Authors: Osborn, Henry Fairfield, 1857-1935

Subjects: Evolution Life -- Origin

Publisher: New York, C. Scribner's Sons

Contributing Library: MBLWHOI Library

Digitizing Sponsor: MBLWHOI Library



View Book Page: Book Viewer

About This Book: Catalog Entry

View All Images: All Images From Book


Click here to view book online to see this illustration in context in a browseable online version of this book.



Text Appearing Before Image:

protoplasm contain-ing a nucleus within which lies the heredity-chromatin(Fig. 12). This passes into the plasmodial condition ofthe Rhizopods, in which the protoplasm increases enormouslyto form the relatively large, unprotected masses adapted to Jennings, H. S., 1906, pp. 318, 319. . Op. cit., pp. 329-335- ^ These two explanations are fully set forth below (see pp. 143-146) in the introduc-tion to the evolution of the vertebrates. ■* Adaptive radiation—the development of widely divergent forms in animals ances-trally of the same stock or of related stocks, as a result of bodily adaptation to widelydifferent environments (see p. 157). ^ Minchin, E. A., 1916, p. 277. EVOLUTION OF PROTOZOA 115 the creeping or semiterrestrial mode of life. From theseevolve the forms specialized for the floating pelagic habit,namely, the Foramiiiijera and Radiolaria, protected by anexcessive development and elaboration of their skeletal struc-tures.^ Less cautious observers- than Jennings find in the


Text Appearing After Image:

Fig. 18. Skeletons of Typical Protozoa. B. Siliceous skeleton or shell of a typical radiolarian, Stauraspis siaiiracantha Haeckel, 170 times the actual size. Owing to their vast numbers, these microscopic, glassyskeletons are an appreciable factor in earth-building. A large part of the islandof Barbados is formed of radiolarian ooze. Photographed from a model in theAmerican Museum. C. Calcareous skeleton or shell of a typical foraminifer. Globigcnna bidloidc; dOrbigny, 30 times the actual size. As the animal increases in size it forms successivelylarger shells adjoining the earlier ones until, as shown in the figure, a cluster ofshells of increasing size is formed. The name foraminifer refers to the manyminute openings, plainly seen in this figure, through which the pseudopodia canpass. Photographed from a model in the American Museum. (Compare Fig. i6,p. 112.) Foraminifera the rudiments of the highest functions and themost intelligent behavior of which undifferentiated protoplasmhas



Note About Images

Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.

3 faves