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POPULAR SCIENCE REVIEW. 
Spontaneous Generation . — The controversy between Messrs. Pasteur and 
Pouchet on this question is not yet extinct, for we find a communication 
from the former in the Comptes Rendus for the 2nd of November, in reply 
to a statement of the latter made before the Academy in September. M. 
Pasteur clearly shows that Pouchet’s experiments are only his own on a 
very much smaller, and less precise scale ; and that in reality they bear 
out M. Pasteur’s views, that there is no such thing as spontaneous 
generation. 
Homologies of the Facial Bones of Fishes. — M. H. Holland makes the 
following statements in regard to these homologies, to which he has been 
led by a study of the embryogeny of fish: — (1) The five facial pieces, 
comprised in the temporo-maxillary wing, tympanic wing, the mandibular 
arch, form two distinct groups, which correspond to two primordial elements 
of the cartilaginous skeleton, visible during the entire period of embryonic 
life. (2) The group proceeding from the anterior cartilage is composed 
of the tympanic and jugal bones of Cuvier, and constitutes the true arch of 
the inferior maxilla, to which it is articulated by its lower portion. The 
posterior group is composed of the three bones called by Cuvier the tem- 
poral \ symplectic , and pre-opercular bones, and constitutes the hyoidean arch. 
(3) The mandibular arch, despite its division, constitutes a whole, which is 
homologous with the tympanic wing, and consequently with the os quadra- 
turn of birds. (4) Similarly the hyoidean arch, notwithstanding its being 
compound, represents a single osteologic element, which corresponds to the 
styloid bone of mammalia. Its great development being due to the com- 
plex part it has to play in connection with the function of respiration ; 
it supports a hyoidean cornu of a compound character, and is connected 
with the opercular wing, and assists in the breathing movements. (5) The 
true temporal of fishes does not belong, as Cuvier supposed, to the hyoidean 
arch ; — the portion which he termed mastoidean is really the squamosal por- 
tion of the temporal. 
TheNervous System of MollusJcs. — M. Salvatore Trinchese lately presented 
a memoir to the French Academy upon the Anatomy of the Nervous Centres 
in Gastropods. We hardly think his assertions will be confirmed by future 
observations. He states (1) that the nervous system of mollusks is com- 
posed of the same elements as that of vertebrate animals. (2) That the 
medullary nuclei found in the sesophagean collar differ from one another 
in structure. (3) That in those types in which the centralisation of the 
medullary nuclei is most marked, the fusion only occurs in half the pedal 
ganglion, those in the upper and lower regions being quite distinct. (4) 
That the nervous element penetrates the substance of the smooth muscular 
fibres of these animals, and terminates in points. 
The Anatomy of the Brain of Lepidosiren annectens. — There are few 
points in the range of comparative anatomy of more interest, or which have 
given rise to more controversy, than the anatomy of the Lepidosiren, of which 
two species have been carefully examined, L. annectens and L. paradoxa. 
Among those who have heretofore devoted themselves to this subject, we 
may mention the names of Owen, Bischoff, and Hyrlt. It is by some 
naturalists regarded as a fish, by others as a reptile, and certainly its cha- 
racters partake so much of those of both classes that it is difficult to say on 
