'in hi;>Mii of tin: i'mtki> statks. 



XXI\', ag. 33, is ;i cluster of Closteriums surrounded by a mem- 

 brane, found by Ralfs; he however questions whether this is n 

 germinating sporangium. 



Encysted clusters of Desmids arc not necessarily evidence of 

 termination. I have found many such cysts enclosing sometimes 



. . . 



only one large specimen, as Euadrum verrucosum, but more fre- 

 quently six or eight smaller Desmids in one cyst ; these were at 

 firsi a source of perplexity. Upon consultation with men and 

 hooks I found Huxley to say: "Encystment is very common 

 among all the OUiata ; and :i species of Amphileptus has been seen 

 to -wallow, or rather envelope a stalked hell-animalcule, and then 

 become encysted upon the stalk of it- prey." 



Prof. Smith write- with reference to a case of' encysted diatonic-: 

 " the group of Navicula seen, are -imply ;i gr< >up that were devoured 

 and their protoplasm digested by an Amoeba. They constantly are 

 ejected in this way from the body of the Amoeba after the nutri- 

 ment has been abstracted, and look like an encysted ma with an 

 envelope complete." 



This subject of multiplication by regeneration is lull of interesl 

 for the microscopist, and open- ;i large and unexplored field. 



The frequenl variations in outline of form in certain species is 

 calculated to mislead, and perhaps BUggest notion- of variation of 

 specie-, hut close observation will soon dispel such notion-, and 

 prove that they are merely temporary results of exhausted vitality 

 in the process "f multiplication by division : they occur mosl fre- 

 quently in the latter pari ot' the summer season. After (regenera- 

 tion through copulation, the zygospores become winter resting 

 spores and lie dormanl until the following spring, then germinate 

 and reproduce the true counterpart of the original form of the 

 species. 



