No. 505] KELPS AND RECAPITULATION THEORY 23 



waves, which lash the plant until the lamina together with 

 the meristem is torn off and there remain simply the stipe 

 and holdfast. 



The stipe remains smooth for a few centimeters above 

 the large branching holdfast, this being evidently a per- 

 sistence of the smooth basal region of the young plant. 

 Some of the lower tubercles, however, disappear, so that 

 the smooth area now extends farther from the base than 

 originally. This portion is terete, but at a length of about 

 a decimeter the stipe becomes flat and strap-like about 

 four times as wide as thick. 



In the younger specimens the proliferations from the 

 stipe and lamina are all small and not very numerous. In 

 the adult they enlarge very greatly and increase in num- 

 bers so as to become by far the most conspicuous feature 

 of the plant. The increase, both in number and size, is 

 most marked toward the growing point, those at the base 

 generally remaining small and scattered. Farther out 

 along the stipe they are found of all lengths up to about 

 12 cm. and of various forms, as figured by Kamaley. 

 They stand as thickly as possible along the stipe ; in some 

 places by actual count upwards of a hundred were found 

 in a single centimeter of its length. Of these only a few 

 were large and more than half less than a centimeter long. 

 Crowded as they are along the edges of the stipe, they 

 never arise from its faces, which are bare except for the 

 tubercles described above. The air vesicles are formed at 

 frequent intervals, providing sufficient buoyancy to keep 

 the plant floating just beneath the surface with the tips of 

 the proliferations emerging. When mature, they are 

 about 30 mm. long, with an average capacity of about one 

 cubic centimeter. Others of the outgrowths remain per- 

 manently small and become sporophylls. The outgrowths 

 on the lamina also increase in size and number, but become 

 neither so large nor so numerous as on the stipe. As 

 noticed by Ramaley, no bladders nor sporophylls develop 

 on the lamina. 



Egregia becomes much branched before it is mature. 

 Although Eamaley suggests that the branching may have 



