384 THE AMERICAN MONTHLY [Nov. 



membranaceous forms like Ulva lactena. Such forms 

 are of course better if placed in simple formalin solu- 

 tion. 



Pliacophycecc do well when placed immediately in 1 per 

 cent formalin in saltwater. The larger forms are better 

 fixed in 1 per cent chrome alum for a few hours (3-6) and 

 then preserved in 2 per cent formalin solution of camphor 

 water. But specimens for crushing may be allowed to 

 remain indefinitely in the chrome alum solution. 



Rliodophyceoi. The coarser forms may be put into any 

 one of the three solutions and be in very excellent con- 

 dition; chrome alum preserves more color than formalin 

 or camphor water. For the finer study, specimens are 

 best left in a concentrated solution of picric acid in sea 

 water for twenty-four hours, then washed, preferably in 

 sea water, for about twenty-four hours more, and pre- 

 served in camphorated sea water. Such genera as Nema- 

 lion, Champia, Rhabdonia, Cystoclonium, etc., respond 

 best to this treatment. Delicate species need very care- 

 full consideration. Griffithsia bornetiana is a most 

 delicate species and, preserved in almost any way, col- 

 lects itself together into a shapeless mass; the cells lose 

 their shape, and it becomes a very uninviting object for 

 study. But place in 2 per cent formalin in sea water 

 with plenty of fluid so as not to be crushed, the cells 

 keep their shape and the whole plant presents a life-like 

 appearance as far as form goes. The color of course 

 departs. The same thing is true of various species of 

 Callithamnion, such as C. baileyi, C. borreri, C. seiro- 

 spermum, etc. Dasya elegans has a way of dropping its 

 hairs on being preserved, and the more delicate species 

 of Polysiphonia break up into short pieces, but either 

 formalin or chrome alum will prevent this if the speci- 

 mens are fairly fresh when put into the preserving solu- 

 tion. — Botanical Gazette. 





