Remarks 0)1 a Variety of Nostcc Priimforvie. 255 



In the straight filaments leading out from the (-enter, the Jior- 

 /iiogoncs in forming are not so irreguiar in shape as those just de- 

 scribed. Near the jjeriphery they are developed in great abund- 

 ance. When fully formed they are not made up of a mass ot 

 closely united cells, but are young plants in which the characteris- 

 tic twisting filaments can be distinctly seen. In some cases these 

 young nostocs will be found at the very outer edge of the thallus, 

 and it is not uncommon to find such a plant covered with other 

 small but fully formed plants. It would seem j^robable from this 

 that the honnogo/ics thac are formed near the periphery can develop 

 into inde])endent thalli before the entire dissolution of the parent. 



There were many things of interest about this collection not 

 directly connected with the nostocs. In almost every case the 

 plants were covered with layers of carbonate of lime deposited 

 from the water in which they grew. Quite a number of diatoms 

 were found in the sediment at the bottom of the bottle, and occa- 

 sionally one would be found inclosed in one of the masses of 

 jelly. Irregular, whitish spots would quite frequently be tound 

 scattered through the gelatinous matter, but strangest of all were 

 the bodies observed by Mr. G. H. Curtis. I can best describe 

 them by saying that they appeared like multitudes of pins with 

 their ])oints all directed toward a common center, where they be- 

 came so numerous that the individuals could no longer be distin- 

 guished. He considered them raphides. I cannot close without 

 at least mentioning that bacteria were found in great abundance in 

 some specimens that had become a little softened by decay. The 

 gelatinous matter of the thallus seemed to make an excellent cul- 

 ture medium. 



