ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
299 
sojourn for a time in the zoological camp. On the other hand, in 
becoming an evolutionist, the zoologist is himself a philosopher : 
“ L’introduction de l’evolutionnisme dans le monde animal, c’est la pro- 
clamation de la predominance de l’esprit et du regne de l’idee.” Man — 
ethically, intellectually, physically — is what he is because of pre-human 
conditions which made him possible ; and in discovering these the 
philosophic zoologist and the zoological philosophers have a great task 
before them. 
Influence of Lecithin on Growth.* * * § — M. B. Danilewsky has experi- 
mented on the effect of adding lecithin to the water containing the ova 
and larvm of frogs. The result is a marked stimulus to growth. The 
lecithin was only present in minimal quantity, and it is not directly 
organoplastic. It seems to stimulate cell-multiplication very rapidly. 
Fishing-Grounds and Fishes of the West Coast of Ireland. f — 
Messrs. E. W. L. Holt and W. L. Calderwood describe the rarer fishes 
found on their survey of the West Coast of Ireland in 1890-91. The 
region seems to be a meeting-place of two faunas, Lusitanian and Scan- 
dinavian. The authors also support the position that “ though there is a 
degree of cold or heat beyond which fish of a given species cannot exist, 
the cause that governs a change of habitat in accordance with latitude is 
mainly one of competition, and not of temperature.” The struggle for 
existence drives the feeblest forms to the least desirable localities, e. g. 
from littoral to bathybial life, and the resemblance of the Arctic to the 
bathybial fish-fauna is explicable on the ground that it has been brought 
about by precisely the same cause, viz. a migration to a more barren 
region. The memoir contains many other points of much interest. 
Use of Heterocercal Tails, f — Dr. Fr. Ahlborn argues that the 
heterocercy of bottom-fishes and the pseudo-heterocercy of surface-fishes 
must be interpreted not as a steering arrangement, but as an adaptation 
for sculling in dangerous proximity to the upper or to the lower limits 
of the water. Tails may be described physiologically as “epibatic” 
(i. e. raising off the ground), “ hypobatic ” (i. e. bringing down), and 
“ isobatic.” The paper is somewhat beyond the scope of those usually 
recorded in this J ournal, but its interest warrants this brief note. 
Tunicata. 
Cell-Lineage in the Segmentation of the Ascidian Ovum.§ — 
Mr. W. E. Castle has made continuous observations on the segmenting 
ova of Ciona intestinalis in order to determine the exact cell-lineage. 
He finds a fundamental error in the work both of Van Beneden and 
Julin and of Seeliger, “Seeliger has determined the dorsal and ventral 
sides of the egg correctly, but reversed the anterior and posterior ends 
in all his figures of the early stages. Yan Beneden and Julin have 
determined correctly the anterior and posterior ends, but have reversed 
dorsal and ventral in all stages previous to the 44-cell stage.” 
Having mistaken the orientation, Yan Beneden and Julin stated that 
* Comptes Rendus, cxxi. (1895) pp. 1167-70. 
f Sci. Trans. R. Dublin Soc., v. (1895) pp. 361-512 (6 pis.). 
% Zeitschr. f. wiss. Zool., lxi. (1895) pp. 1-15 (1 pi.). 
§ Proc. Amer. Acad., xxx. (1895) pp. 200-16 (2 pis.). 
