304 ULVACE^E. 



" Fronds often two feet or more long, and from a line to 

 two or three inches in diameter, tapering at base, at first 

 fixed by a minute root, afterwards detached and freely floating, 

 inflated, variously waved or curled, of a full green colour, 

 fading to yellowish, and finally white." Harv. 



ef In the earliest stage of their developement, the tapering 

 filaments consist of a single series of cells placed end to end. 

 Each of these cells afterwards becomes bisected by a longitu- 

 dinal line, and other lines subsequently appear, so that the 

 original cells are ultimately divided into several, each of 

 which, in its turn, enlarges, and is in like manner divided. 

 From the continued growth and unlimited division of the 

 cells the filaments increase to an indefinite size, soon lose 

 their original confervoid character, present a reticulated ap- 

 pearance, and, instead of being attenuated, become cylindrical 

 and hollow. 



" In each cell or articulation of the filaments, and when 

 these are not thicker than a horse hair, a dark central nucleus 

 is gradually developed, which, there can be no doubt, under- 

 goes repeated division in the same manner as the reproductive 

 globules of the Ulvcs. These nuclei often germinate while 

 still enclosed within the cells in which they were developed, 

 and while the parent filament retains all its freshness and 

 vigour, and give rise to the pointed and tapering filaments 

 first described ; which, in this state, after the rupture of the 

 parent cells, and while their bases are fixed within them, one 

 filament in each, bear a strong resemblance to a parasitic 

 Conferva. 



" This developement, division and growth of cells and repro- 

 ductive bodies, appears to be going on continually and suc- 

 cessively, so that most specimens of the plant present ex- 

 amples of each different stage of its formation. 



" The Enteromorpha intestinalis would appear to have a 

 twofold relation to the Conferva in its young articulated 

 filaments, and to the Ulvce in its reproduction from globules 

 which undergo repeated division. The tautology of the 

 specific name is objectionable, and that of lacustris might be 

 substituted for it." Hass. 



