300 



Profs. Percy Frankland and Marshall Ward: 



0'4 p per minute if constant. But obviously the rate was not con- 

 stant, as the table and curve show (see fig. 27). 



FIG. 27. 



I made the following observations in addition to see if the varia- 

 tions were connected with cell-division as suspected. Up to 11.17 

 no septum was really visible* in the young filament, but a distinct 

 median one was seen at 11.30 dividing the filament into a proximal 

 and a distal half. By 12.10 a second septum was clearly visible bisect- 

 ing the distal half, but none was as yet visible in the proximal half 

 to which the spore membrane still clang. At 12.38 the proximal 

 segment was also divided by a visible median septum. At 12.47 I 

 measured both the primary segments and found the proximal, recently 

 divided, one shorter than the distal one, in the ratio of 15 to 18 ; 

 that is to say, the whole filament measured 59'86 /t, as seen, but that 

 part of it to the proximal side of the first septam was only 27 /t, that 

 to the distal 33 /t in length ; so that already the symmetry of the 

 filament was disturbed, and further measurements confirmed this. 



At 12. 56" the proximal segment had one septum, now very distinct, 

 and measured 30'5 /JL, whereas the distal one was by this time pro- 

 vided with two visible septa, and measured nearly 37 /*; at 1.5 P.M. 

 the proximal one still had but one septum visible, and measured 

 32'5/i, whereas the distal one, with its two visible septa, measured 

 42-5 /*. 



Hence we see the two primary segments resulting from the first 

 division of the germinal filament grow and (so far as visible segments 



* Probably thin septa were present, but they were not visible in the living and 

 rapidly growing filament. 



