. The dawn of life [microform] : being the history of the oldest known fossil remains, and their relations to geological time, and to the development of the animal kingdom. Paleontology; Life; Paléontologie; Vie. WHAT IS EOZOON 80 another by nothing else than the proper walls of the chambers, —which, as I shall presently show, are traversed by multi- tudes of minute tubuli giving passage to pseudopodia,—the coalescence of these pseudopodia on the external surface would suffice to lay the foundation of a new layer of sarcodic seg- ments. But where an intermediate or supplemental skeleton, consi
. The dawn of life [microform] : being the history of the oldest known fossil remains, and their relations to geological time, and to the development of the animal kingdom. Paleontology; Life; Paléontologie; Vie. WHAT IS EOZOON 80 another by nothing else than the proper walls of the chambers, —which, as I shall presently show, are traversed by multi- tudes of minute tubuli giving passage to pseudopodia,—the coalescence of these pseudopodia on the external surface would suffice to lay the foundation of a new layer of sarcodic seg- ments. But where an intermediate or supplemental skeleton, consisting of a thick layer of solid calcareous shell, has been deposited between two successive layers, it is obvious that the animal body contained in the lower layer of chambers must be completely cut off from that which occupies the upper, unless some special provision exist for their mutual communication. Such a provision I believe to have been made by the extension of bands of sarcode, through canals left in the intermediate skeleton, from the lower to the upper tier of chambers. For in such sections as happen to have tra- versed thick deposits of the intermediate skeleton, there are generally found passages distinguished from those of the ordinary canal-system by their broad flat form, their great transverse diameter, and their non-ramification. One of these passages I have distinctly traced to a chamber, with the cavity of which it communicated through two or three apertures in its proper wall; and I think it likely that I should have been able to trace it at its other extremity into a chamber of the superjacent tier, had not the plane of the section passed out of its course. Eiband-like casts of these passages are often to be seen in decalcified specimens, traversing the void spaces left by the removal of the thickest layers of the intermediate skeleton. " But the organization of a new layer seems to have not un- frequently taken place in a much more considerable
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