20 



fnail, can only be rendered productive by contact with the oppofite powers of 

 other filaments. Thus this apparently infignificant tribe affords an unique and 

 wonderful analogy between the reproduction of the animal and vegetable king- 

 doms, and is a finking evidence that " the power of God is over ad his works, 

 and is feen to the aftonifhment of man in the variety of his wonders." 



Hydrodictyum. — Chaque articulation devient elk mime une nouvellc 

 plante qui s'etend commc un reseau, 



C. reticulata was firft feparated from the Conferva under the generic name of 

 Hydrodiclyon by Dr. Roth, as is already mentioned, and no other plant has been 

 fince difcovered with whicli it can be aflbciated. Its fu'rprifing mode of propa- 

 gation is mentioned in my description of this fpecies, and I Shall therefore only 

 repeat that we are wholly indebted to the fcrutinizing talents of M. Vaucher 

 for this important difcovery. 



Polysperma. — Les grains font repandues en tres grand nombre dans /'/»■ 

 tirteur d'ttn tube renjli, non tranfparent ct ramifii. 



C. fluviatilis and glomerata are the only fpecies which M. Vaucher has been 

 able to refer to the prefent genus, to which however he fufpefts that feveral 

 others alfo belong. He obferved that the filaments of C. fiuviatilis are lined 

 with minute beaded threads, which at length divide, and each bead then be- 

 comes a Separate granule. He thinks it probable that a part of thefe grains, 

 although they cannot be diftinguiflied from the others, are male organs which 

 die away as foon as they have performed their office ; a conjecture that feems 

 rather ingenious than probable. He however afcertained, by a courSe of well 

 directed experiments, that at lead a part of thefe granules are true feeds, and 

 traced their growth from the germination till they refembled the ,parent plant 

 in all reSpedTs. Thefe globules, both in their connected and detached State, 

 may be readily obferved by cutting and prefiing the filaments, and, though I 

 have failed in rhy endeavours to witnefs their germination, I cannot in the leaft 

 doubt the accuracy of M. Vaucher's obfervations, or fuppofe that this fpecies 

 is not propagated as he defcribes. Tufts of young feedlings may be alfo fre- 



