NOTES ON NOSTOCHINE.E. 191 



but transparent, inibedclcd in a continuous, amor- 

 phous, gelatinous matrix. The cells seemed of two 

 sizes, with eight smaller and one larger, or perhaps 

 spermatic cells, that appeared brighter than the rest. 

 On the outside of the envelope, and firmly adhering 

 thereto, were small spores that were nearly black re- 

 sembling the seeds upon a strawberry. 



This Nostoc is a typical genus of the Nostochineas, 

 distinguished from the allied genera by the definitely 

 formed pellicle tliat encloses the fronds Thuret 

 states, that the pellicle of the fronds bursts, allowing 

 the gelatinous mass to escape, and the filaments to 

 spread abroad in the water, thus reproducing. Van- 

 cher says, after bursting the}- are endowed with the 

 ])ower of moving slowly along lengthwise, and that 

 after a tinu: the cells cease to mo\'e, and a new gelat- 

 inous pulp with an envelope is formed around each 

 piece. My observations do not accord with theirs, as 

 I can find no reproduction in that way. Yet it may 

 be tlial undiM' other circumstances their manner of re- 

 {)ro(lucli<)n nii;^ht change. 1 noticed that at the point 

 of adhesion of a spore a few cells would ooze out from 

 the gelatinous mass, among which would be one or 

 [\\n of the larger cells, and a new nostoc would grow 

 adhering to the mass for a short time, or jierhaps a 

 few ciax's, when it would usnall)- split oM from the parent 

 .'tnd take up a separate existance. Man\' times how- 

 e\'er the\- would adhere to each other in tlieir growth 

 sf) that as many as ten or twelve would sometimes be 

 attached, thus forming shapeless lobed masses. 



The near alliance of this alga ti^ the Collonia. has 

 attracted much attention, and some authors even as- 

 sert that it is only a \ariety of the same sj)ecics. 

 The memoir ui' Sachs on the subject is deserving t)f 

 attention. Many species of this alga are found grow- 

 ing in water, sometimes in brackish water, or e\'en in 

 hot springs. Others crow on the naked soil or rocks 



