24 



gaade prolifere; etifiri Us fe feparent pour aller former ailleurs uu nouvel indi- 

 vidu femblable a celui fur lequel ils ont pris naiffance ; mats j avoue que je n>/< 

 pas vu defiparation, quoique je n'aie aucun lieu de dourer qu'elle ne s'opere." 



I have now before me the variety mentioned in my defection of C. rivu- 

 iJis*, and more fully defcribed in my fynopfis, with fhort fpirie-like proceffes, 

 refembling both in fize and fliape thofe figured on Voucher's f P. crljpa. If, as 

 M. Vaucher imagines, thefe are a proliferous progeny, it muft be fu| pofed that 

 they would refemble the parent, not only in their joints, but alfo in the fhape 

 of the filaments; the latter are, however, cylindrical throughout, and the for- 

 mer, at leaft in f me fpecies, are reprefented as remarkably acuminated; and 

 of the proceffes of C. rivularis at this time under my obfervation, many, not the 

 tenth of an inch in length, are as pointed as poffible, although the diameter at 

 their bafe equals that of the main filament. I examined this variety during a 

 fortnight, but could not obferve that the ramuli at all encreafed in length, or 

 fuffered any change, till at the end of that period, the whole died away, and 

 difappeared together. M. Vaucher has not noticed how far their length bears 

 any regular proportion to that of the main filament, and he admits, contrary to 

 his generic definition, that he has never feen them feparate from it. In the 

 defection of P. fioccofa, which is probably the fame with my C. punSalis, he 

 fays, « Elle fe raultiplie avec une telle rapidite qu'elle couvre au bout de 

 quelques jours des places confidences dans lefquelles on ne l'avoit pas d'abord 

 apercue," and yet he could never difcover any proliferous tendency, or any other 

 means whatever by which this increafe was effected. I therefore wonder at 

 this fpecies having been arranged with the Prolific, but M. Vaucher poflefles 

 the rare merit of never concealing or diftorting truth to ferve a favorite theory, 

 and expreffes himfelf throughout fo doubtfully of the ufe and nature of the 

 branch-like proceffes, that it is rather furprifing he fhotild have founded the 

 genus with fuch an uncertain character. It is neverthelefs probable, from M. 



* PriKfcra rivukrh of Vaucher differs from this fpecies in its much longer joints, 

 t See the drawing of this fpecies in my fupplemeatary plate B. 



