THE BEGINNINGS OF LIFE. 149 



may issue near the opposite extremity, either from the 

 same or from the other side. Then one or other of 

 various modes of development may occur: — 



a. The filament may expand into a long or short 

 single cell, and then may segment into conidia, which, 

 after a little delay, themselves undergo a process of 

 germination. 



b. Or the filament may continue to grow, forming 

 dissepiments, or undergoing a partial process of division 

 at intervals. The terminal division of such a filament 

 may then divide (as in the last case) into globular or 

 ellipsoidal conidia. Many of the filaments may in 

 addition send out lateral prolongations, and some of 

 the shorter of them may also break up into conidia. 



c. The changes already mentioned are to be seen in 

 those corpuscles which germinate beneath the covering 

 glass, but where the process occurs outside the edge of 

 the glass, the resulting growth is much more luxuriant. 

 The larger filaments develop branches of the second, 

 third, and fourth order — all being made up of oblong 

 cells produced by partial segmentation. And any of the 

 terminal ramifications may break up in various ways 

 into reproductive units or conidia. Before tliis process 

 occurs, M. Trecul says : ^ The extremities of the fila- 

 ments ordinarily assume an indistinct but bright and 

 highly refractive aspect, similar to what the conidia 

 themselves preserve after the process of segmentation.' 

 Where the filaments remain in the recumbent position, 

 they may develop either one or two series of conidia j 



