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POPULAR SCIENCE REVIEW. 
extreme has also been re-developed in Enchytrseus, Lumbricus, Fabricia, 
and a Nereis, common on our coasts. In the majority of these cases he 
has seen food taken again, and in all he has seen the incurrent anal stream 
recommence. In one instance he found (August 21) a remnant con- 
sisting of five segments of a Nais. It went through a rapid growth ; the 
eyes were developed about the 22nd, and the mouth opened about the 23rd. 
The Functions of the Brain and Frontal Ganglion of Insects . — At a late 
meeting of the “ Societe Philomathique,” a paper -was read by M. Ernest 
Faivre describing the experiments he had undertaken, to ascertain the 
offices of the above structures. We learn from this communication, 
which contains the details of several vivisections : 1st, that the brain is 
the centre from which the direct and reflex impulses proceed ; and 2nd, 
that the frontal ganglion — which is merely an enlargement of the stomato- 
gastric nerve — is but the conductor of impressions. On irritating the 
stomato-gastric nerve of a Dyticus behind the ganglion, decided con- 
tractions of the pharynx were produced ; but when the commissural fibres 
connecting the ganglion with the brain were divided, these movements were 
no longer brought about by irritation. When the stomato-gastric was cut 
at the level of the crop, the latter became distended with gas ; but when 
this section was made in an insect whose fronto-cerebral filaments had 
been divided, tympanitis was not evident. The only 'peculiar property 
which the frontal ganglion appears to have, is that of producing move- 
ments by direct excitation after the commissural fibres have been removed. 
The Spontaneous Alteration of Eggs . — The newest and perhaps the most 
forcible objection to the theory of spontaneous generation, is that embodied 
in the late contribution of M. Al. Donne to the Academie des Sciences. 
Having selected a number of hen eggs, M. Donne divided them into two sets: 
in one, the eggs had the upper end pierced by a small aperture, in the other 
they were left entire. Both were now exposed for some time to the 
influence of the atmosphere at a temperature varying from 10° to 36° 
centigrade, and were then examined. Those which had been opened pre- 
sented all the signs of putrefaction, mould and organized beings of both 
kingdoms were present in abundance. The other eggs, however, remained 
unaffected, and when opened at their extremities, exhibited an empty space 
(that which in all eggs contains pure atmospheric air) ; but there was 
no odorous exhalation, nor was there a trace of any living being, animal 
or vegetable ; but on being exposed for a few days they showed symptoms 
of putrefaction, and Infusoria and vegetable organisms were detected in 
them. Thus we see, that here, although a highly organized and easily decom - 
posable material was exposed to air (that of the egg), and to a considerable 
temperature , no development of organized beings eventuated . He has also 
discovered, that if an egg be coated with collodion, so as entirely to prevent 
the entrance of atmospheric air, and then shaken, so as to destroy its 
internal physical structure, all the chemical phenomena of decomposition 
appear ; but not the slightest trace of either animal or vegetable life can be 
discerned even with the assistance of the microscope . If these observations 
of M. Donne be corroborated, they will throw more light on this much 
debated question than any previous experiment that we are acquainted 
with, not excepting even that of Schultze. 
