6S 



the restinc condition £ire very snie.ll, averacing, perhajiij , /•^'/^ 

 in diejneter. In structm^'e they resemble the nuclei of the 

 older vecetative cells. 



The chances in the apical and middle cells consist 

 ma,inly of (1) a e^'es-t increase in length, (2) slight inb- 

 crease in breadth, and (3) the distribution of the proto- 

 plasm and inclusions over a much lejfger a^rea. 



In the hasal cell, besides an increase in size, the 

 most striking changes are those of shape. These changes 

 depend to a large degree on tlie substratimi. In ca,se the 

 sporeling is attached to some soft body, such as another 

 alga, the bg-sal cell remains somewhat top-shaped, with the 

 pointed end 5,pplied to, or in some cases vredged into the 

 substratum (figs. 164,165,166,167). If, however, the 

 sporeling is attached to a hard body, such as glass or stonc-y 

 the bascil cell becomes greatly elongated, in some cases 

 coming to equa,l in length ?,11 the rest of the sporeling 

 (figs, 168,169). V/lien this occurs, tlie basa,l cell resem- 

 bles very strikingly a rhizoid of tlie older plant. 



MlTien the stage just described is readied, there seems 

 to come a natural pause in the life-cycle. In a state of 

 nature, a great majiy more sporelings etre found in the 3- 

 celled stcige tlian in any other, indicating that this stage 



