IP s t e I 5 t a 257 



plant maintains through life a form very near 

 the primitive type of kelp structure, there is 

 not in this case the interest attached to the 

 tracing out the development of a complex 

 adult form like Egregia from the simple juvenile 

 form that there is in the more specialized forms 

 The young forms are very much like the older 

 except in size and the tissues of the adult are 

 already developed in plants as small as the 

 smallest in the writer's possession. As in other 

 kelps the juvenile forms of this species may 

 be recognized quite readily at least when no 

 smaller than 5 centimeters. At that time they 

 are clearly differentiated from most species by 

 the absence of the characteristic marks which 

 distinguish other genera. They are most sim- 

 ilar to Nereocystis and the similarity does not 

 disappear, though they become easily distin- 

 guishable, until the laminae of that genus begin 

 to divide. In smaller specimens they may be 

 distinguished by the beginning of the pneumat- 

 ocyst of Nereocystis which is discernable in 

 plants of about 3 centimeters. In specimens 

 smaller than that it seems doubtful to me 



