336 
ORIGIN or INFUSORIA. 
plates covered with glycerine, that, like Pouchet, he found 
grains of starch and spores of cryptogams, and much less 
frequently what appeared to be eggs of invertebrate animals, 
but that “ both eggs and spores may be to be said of rare occur¬ 
rence.” It will, however, be asked whether the eggs of infu¬ 
soria could be discovered by the methods employed. M. 
Balbiani gives a table (which will be found at the close of 
this article) of the number and dimensions of the ova pro¬ 
duced by various animalcules, and, as will be seen on refer¬ 
ence to our account of his remarks in No. 6, p. 468, he 
describes them as so transparent that their form can only be 
made out by employing dilute acetic acid to augment their 
cohesion and refractive power. It would probably be impos¬ 
sible, especially without the employment of reagents, to see 
those bodies after they had been caught in a film of glycerine, 
or, still worse, in one of olive oil, which MM. Joly and Musset 
employed, and we should certainly not be warranted in 
assuming the non-existence of infusorial ova in consequence 
of the failure of a comparatively clumsy means of investi¬ 
gation. 
With reference to the appearance of Bacteriums or similar 
objects in infusions apparently free from living germs of any 
kind, we may observe that scarcely anything is known con¬ 
cerning these minute organisms. Ehrenberg placed them 
among the animals, and inferred their possession of a plurality 
of stomachs ! Other investigators regard them as vegetables, 
and Mr. H. J. Clark, of Cambridge, U.S., claims some of 
them as nothing more than portions of decomposed muscular 
fibre or tissue. Probably these objects, which assume the 
form of exceedingly minute chains, more or less flexible and 
movable, differ widely in their real nature, and some of them 
may not be alive at all. 
M. Pouchet now deposits with the French Academy a 
fresh batch of printed and MS. matter on heterogenesis, to 
compete for the Alhumbert prize, and MM. Joly and Musset 
send in for the same purpose their c Nouvelles Etudes sur 
PHeterogenie/ a brief account of which is given in ‘ Compte 
Rendus/ September 22, from which we select the most inte¬ 
resting facts. They took a series of flasks holding one litre, 
and containing forty grammes of the same decoction, together 
with air that had been passed through red-hot tubes (air 
calcine ). Then, following the method of M. Pasteur, they 
caused a little tube containing gun-cotton, charged with dust 
from the air, and “ subjected to the action of burnt air,” to 
fall into flask A. The neck of the flask, also filled with the 
burnt air, was sealed in a lamp. In flask B, prepared in the 
