1880.] 



MICEOSCOPICAL JOUENAL. 



83 



prepared over a year ago, that ap- 

 pear to be as bright and pure, as 

 when they were mounted. Con- 

 trary to the experience of some 

 others, I have not found that the 

 benzole has any bleaching effect, 

 and I have used it with damar, in 

 preference to the usual balsam. 

 Slides prepared with damar, how- 

 ever, should have a thick ring of 

 varnish run around them, as the 

 damar is brittle, and should not be 

 trusted alone, to hold the covering 

 glass. W. 

 



Notes on Fresh-water Algae. 



(,CYLINDROCA PSA .) 



Y. Cylindrocajpsa is the name 

 of a genus of recent creation by 

 Prof. Reinsch, of Silesia. It is re- 



presented by a single European 

 species, found in a pond near the 

 city of Breslau. A plant evidently 

 belonging to this genus is frequent- 

 ly met with on my rambles. My 

 hrst note of it dates 1875. Have 

 found it repeatedly every year 

 since, and have received specimens 

 from Buffalo and Niagara, N. Y., 

 from localities southward as far as 

 Florida, and westward as far as Co- 

 lorado ; but never found it in good 

 fruiting condition until June 20th, 

 18Y9, in this vicinity. The plant 

 is always found in company with 

 others. Young plants attach them- 

 selves to older filaments of their 

 own, or of another kind, or to 

 blades of grass, etc., upon which 

 they grow ; but when matured to 

 some length, they separate and 



form floating masses. They retain 

 the companionship of other char- 

 acters. 



The plants are composed of a 

 simj)le series of oval, or elliptical, 

 green, granular cells, surrounded by 

 a rather firm, colorless sheath. The 

 oogoniums are developed from the 

 vegetative cells, and each one con- 

 tains primarily an oval, and then a 

 spherical spore. The antheridia, 

 which I have not seen satisfactorily, 

 are described by Reinsch as being 



formed in the same sheath by the 

 division of a vegetative cell into 

 two or four parts, which stand side 

 by side, or over one another : each 

 develops two spermatozoids, of yel- 

 lowish color, spindle-shaped, on the 

 end colorless, with two vacuoles and 

 two celia ; when ejected they find 

 their way to the oospore and fruc- 

 tify it ; he add, the oospore is thus 

 produced and clothed with a dou- 

 ble membrane ; it changes color to 

 reddish yellow, and then takes a 



