AND INHERITANCE IN PEDIASTRUM. 



423 



lobe. These are probably thirty-two-celled colonies, though they 

 are too irregular to permit accurate counting. The colony shown in 

 Fig. 31 is quite young, while that shown in Fig. 32 is well on toward 

 maturity. The cells attached by only one lobe have gone through 

 their whole development in apparently normal fashion. 



T 



31 



?.9 



♦ W* 



%*• • 



Figs. 31 and ;i2. PediastruDi aspcrmn. Young colony showing as in 

 Figs. 29 and 30 cells which are without their normal contact and pressure 

 relations in the colony and have still developed the characteristic form for 

 the species. Fig. 31 X about 500; Fig. 32 X about 175. 



Fig. 33. P. asperum. Like the last two figures, but with a cell attached 

 in reversed position by one of its peripheral lobes and still showing the typical 

 form. X about 225. 



Fig. 34. P. asperum. Colony with one of its peripheral cells reversed 

 but showing one typical long spine directed toward the center of the colony. 

 The other is blunted by contact with an adjacent cell. X about 425. 



Most interesting is the case shown in Fig. 29, where we have a 

 cell attached only by one of its peripheral lobes and to a peripheral 

 lobe of a peripheral cell of the colony. Here the basal lobes are 

 both peripherally placed and yet have retained their blunter form. 



