1880.] 



MICKOSCOPICAL JOURNAL. 



Wolle, to whose labors we are in- 

 debted for a knowledge of many 

 new and interesting plants, belong- 

 ing to the fresh-M'ater Algae. With 

 the cooperation of such an able and 

 enthusiastic worker, they cannot 

 fail to be of interest to the general 

 student, and of sterling value to 

 the specialist. 



We are indebted to Mr. Wolle 

 for the excellent delineations of 

 Aptogonimn^ and also for the obser- 

 vations upon the reproductive pro- 

 cess of that plant, which are the 

 results of original investigation. 



I. Aptogonium Baileyi, Ilalfs. 

 This is one of the filamentous des- 

 niids, and one of the most beauti- 

 ful. So far as known, it is only 

 found in America. The 

 illustrations which we 



five, are more true to 

 [ature than any we have 

 seen elsewliere. A, Fig, 6, 

 represents one side of a 

 filament, B the same fila- 

 ment, seen with an angle 

 toward the eye. Previous 

 to conjugation the chlo- 

 rophyll, w^hicli is homo- 

 geneous in the young 

 plant, separates into two 

 oval portions (C) ; after 

 some time these unite, 

 their contents flow to- 

 gether, and the spores de- 

 velope. At first the spores 

 are small, oval bodies 

 25.4/^ 30.48/^ in diameter, 

 within the cells or joints 



I of the ordinary filament. As the 

 I spores mature they enlarge, press 

 I the walls around the aperture to- 

 ! gether and the sides of the fila- 

 ! inent apart, until they become 

 I nearly three times their original 

 diameter {F) . When fully ma- 

 tured, the filaments separate in the 

 middle, and release the spores. A 

 filament from which the spores 

 have escaped is represented at G. 

 DD are end views of cells. This 

 alga was first found by Professor 

 Bailey. It is distinguished from 

 others of the same genus by its 

 margins, which are not crenate. 

 An alga found in Silesia, Dismid- 

 ium coelatum^ Kirchner, has its 

 margins also entire, but it diifers 



K.bbo 



Fig. 7. 



Fig. 6. 



from our Aptogonium in the 

 form of the cells, which are 

 quadrangular, not triangular 

 in front view. 



II. Desmidium Swartzii. 

 This is one of the most com- 

 mon of our desmids. The 

 cells are connected into long 

 filaments, which might not 

 at first be recognized as made 

 up of a series of desmids. A 



