60 FRESH- WATER ALG^ OF THE UNITED STATES. 



final articles obtusely rounded; polyspores racemose, 

 crowded on the fertile branches, oval or somewhat ovate. 



Var. BEARDSLEI, Wolle. 



In the Bull. Tor. Bot. Club, January, 1879, we described 

 a singular form, remarkable for size, having a diameter of 

 25-50 yw, three to six times more robust than the typical C. 

 violacea. It occurred as an undergrowth, intermingled with 

 Lemanea, which was fringed with the parasitic C. violacea. It 

 was sterile, and may be an abnormal development. 







Collected by Dr. Beardslee, Painesville, Ohio. The var. 

 expansa occurs frequently on stones in outlets of limestone 

 springs, Pennsylvania. 



A favorable opportunity for the study of the growth of 

 the typical C. violacea occurred in an aquarium supplied with 

 flowing water. It flourished for several years. The plants 

 developed on the glass-sides. Eeferring to Plate LXVIII, 

 fig. 1, the plant, natural size on Lemanea; fig. 2, natural 

 size on glass ; fig. 3, plants magnified 125 diameters ; figs. 4, 

 5, clusters of carpogons (polyspores or sporangia) emitting 

 gonidia which float about in the water until they find a place 

 for rest ; fig. 6, a scratch in the glass, with five gonidia lodged 

 and multiplied by the process of cell division until at the 

 end of two weeks, dark, sack-like forms were produced 

 8-15 mm in length. A single gonidia measures 2.5 yw, or 

 one ten-thousandth part of an inch, hence in one of these 

 groupings no more than one-fourth of an inch square there 

 would be in a single layer 625, 000 small cells or gonidia. 



The purpose of this rapid cell multiplication appears to 

 be a provision to make a bed for a new growth. Placing 

 one of the larger groupings (fig. 6) under higher magnify- 

 ing power, the development of a young growth becomes 

 evident (fig. 7) and soon the whole space is covered with 

 young plants, fig. 8. The violet color of the species is 

 traceable in all the stages of growth. 



Plate LXVIII, figs. 9, 10, represent var. expansa; figs. 11, 

 12, groups of carpogons (polyspores), fig. 13, natural size of 

 plant. Fig. 14, var. Beardslei magnified 125 diameters. 



CHANTRANSIA HERMANNI, (Eoth) Kg. 



Caespitose, pale, rosy purple, about 6 mm long, branches 

 erect, patent with cuspidate or piliferous ends ; articulation 

 3-6 times as long as wide ; 9-12 yu thick. 



