SCIENTIFIC SUMMARY. 
141 
filled with extremely fine granules ; it is smaller than even an encysted 
microzoan, and presents at first no traces of mtemal organs. After having 
remained stationary for some time the viteUiis at length commences a series 
of gyrations, and these are seen to occur beneath its envelope which is 
deprived of cilia. After a while one sees the pitnctum saliens which is charac- 
terised by rhythmic movements, and must not be confounded with the heart 
of encysted microzoa. Finally, embryonic movements make their appearance 
and the young animal springs from the egg. M. Pouchet ridicules M. Coste’s 
notion that the contractile reside is an aquiferous propelling organ ; for, says 
he, if this were the case, why should an infusoria which is encysted, and 
hence cut off from all connection with the surrounding element, possess this 
body ? He terminates his memoir with the following conclusions : — 
1st. If cihated infusoria are accidentally introduced into an experimental 
maceration, they play no part in the operations of heterogeny. 
2nd. Such infusoria are destroyed by the very first processes of fermenta- 
tion which are set up in the liquid. 
3rd. The peUicle on the surface of macerations is a genuine loroligerous 
stroma for the development of ciliated microzoa. 
4th. When the stroma is undeveloped no infusoria will be formed. 
5th. Neither the ciliated infusoria which have been experimented on, nor 
their cysts, nor their ova, ever travel through the filter. 
6th. The multiplication of infusoria does not take place by fission to the 
extent that has been imagined. 
Re-distribution of the Genera of the Order Ruminantia. — It seems a pity 
that zoologists do not base their classification upon pecuharities of internal 
structure, rather than of external form. That a scheme of arrangement on 
the latter foundation is occasionally unsound, has been shown by M. Milne 
Edwards. He contends that the musk deer are truly cervine, and that the 
presence of canine teeth is not confined to these species, which, on the other 
hand, have the stomachs and uterine apparatus of the deer-tribe. He also 
considers that the genus Tragulus does not belong to the Kuminant order at 
all, and ought to be ranked among the Pachyderms, for it has but three 
stomachal cavities, and the placenta is diffused over the entire surface of the 
uterus, and not limited to certain portions, as in the Euminant group. — Vide 
Camptes Rendus, No. 6. 
Pisciculture in Brussels. — The experiments which have been in process of 
being carried out in the latter city during the past five years, have been 
attended with the most satisfactory results. The ova which were originally 
sent from the well-known establishment at Huningue, have not only reached 
a state of development seldom attained under natural conditions, but have 
deposited both milt and ova ; and these in their turn have given rise to an 
enormous development of young fish, so great, indeed, that the authorities 
have been quite taken by surprise. We understand that some of the trout 
removed from the ponds last November, weighed as much as 8lb. This 
looks promising, and must prove encouraging to those who, in opposition to 
numerous difficulties, are endeavouring to introduce fish-culture into these 
countries. 
A New Classification of Birds to be based upon the principles of morpho- 
logy has been proposed by M. Segoud. He has already constructed a classi- 
