THE BEGINNINGS OF LIFE. 143 



ference can be detected between them and some forms 

 of Bacteria, so that many units are to be met with in 

 various infusions to which either name might be 

 applied with equal justice. Torula-forms appear and 

 multiply, moreover, in the midst of homogeneous gela- 

 tinous films or in the midst of. jelly masses, just as 

 obviously (if not quite so frequently) as .B^m'^-forms, 

 which, when they grow in the latter manner, often 

 constitute masses known by the name of Zoog/^a. 



It is impossible for us to assign any ultimate reason 

 why one rather than the other of these forms should 

 manifest itself. We can only observe that in some 

 solutions Bacteria most frequently present themselves, 

 whilst in others Torulte are most prone to occur. It 

 has been known, for instance, since the time of 

 Dutrochet that the organic forms met with in acid 

 and alkaline or neutral solutions vary ; and it has been 

 frequently observed by others, that ToruU are most apt 

 to present themselves in slightly acid solutions. Again, 

 whilst the most putrescible solutions almost invariably 

 yield Bacteria, the same fluids, after their fermentability 

 has been impaired by the influence of heat, may en- 

 gender nothing but Torula 1 . Torul<e are generally 



1 M. Pouchet frequently insisted upon the fact that exposure of the 

 same fluid to higher atmospheric temperatures (by increasing the fer- 

 mentability of the fluid) rendered it most prone to yield Bacteria, 

 although at lower temperatures it would yield Torulce and Fungi 

 ( Nouv. Exper.' p. 179). And, similarly, when Torula are in the habit 

 of vegetating into Fungi at lower temperatures, ' si la temperature est 



