ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
295 
compose the similar tissue of such a very different animal as the 
crayfish. This resemblance suggests to them that the three cell-elements 
of the frog have arisen by the differentiation of a primitive homogeneous 
sporadic mesoblast. With regard to the physiology of the cells, the 
extra-cellular nature of the eosinophile cells is pointed out. This cell 
is in short a unicellular gland which preserves intact the initial step of 
the primitive process, contact with its prey. The hyaline cell also 
effects contact with its prey, but the extra-cellular discharge is 
insignificant or absent. 
Morphology of the Cell.* * * § — Herr G. Schlater was by a misprint in 
the original spoken of as Schloter. 
y. General. 
General Physiology, y — Prof. Michael Foster has a review of 
Verworn’s J work on general physiology, to some point sin which we have 
already called attention. § Prof. Foster thinks that the author exaggerates 
the value of the point of view of cellular physiology. He thinks that, 
important as is the idea of the cell viewed as a morphological unit, 
it is of much less importance when dealt with as a physiological unit. 
The reviewer is of opinion that the author is quite wrong in taunting 
physiologists with the methods of inquiry which they have adopted 
during the last half century. He urges that the application of exact 
physical methods to the study of muscles, so far from having brought 
us to a point beyond which we cannot go, seems just now to be 
opening up the way to fruitful conceptions of the intimate nature of 
muscular contraction. As to blaming physiologists for their compara- 
tive neglect of the lowest invertebrate forms, experience and reflection 
have shown Dr. Foster that, after all, the physiological world is wise 
in spending its strength on the study of the higher animals. He 
thinks that the contraction of a striated muscle is easier to grasp and 
understand than the amoeboid movements of the lowest forms. At the 
same time the reviewer concludes that this contribution to general physio- 
logy is a volume to be welcomed by all. 
Outlines of Zoology. || — Mr. J. Arthur Thomson has produced a 
second edition of his text-book, the figures in which are a decided 
improvement on those in the first. He states in his preface that he has 
endeavoured to take advantage of the suggestions of kindly critics. 
The book is intended to serve as a manual to the student of zoology, 
for use in the lecture-room, museum and laboratory, and as an accom- 
paniment to several well known works cited in the Appendix. Mr. 
Thomson appears to be fortunate in having the assistance of numerous 
authorities on subjects which they have made especially their own. 
Vertical Distribution of Pelagic Life.^F — Prof. A. Agassiz, while 
on a visit to the Bahamas, thought that he could not select a better spot 
* Arch. f. Mikr. Anat., xliv. (1894) pp. 249-58 (1 pi.). 
t Nature, li. (1895) pp. 529-30. 
X 1 Allgemeine Physiologie. Ein Grundriss der Lehre vom Leben,’ Jena, 1895. 
§ See ante, p. 40. 
II ‘ Outlines of Zoology,’ Edinburgh and London, 1895, 820 pp., 266 figs, in text. 
Bull. Mus. Comp. Zool., xxvi. (1894) 203 pp. (47 pis.). 
