270 BOTANICAL GAZETTE [SEPTEMBER 
two others, and the fourth with one other. Three of the conjuga- 
tion branches formed a triple connection, and two other cases of 
triple connection were found on the same slide. The cells repre- 
sented in fig. 2 also presented an interesting study in reproduction. 
One cell was here monopolizing the energies of two cells in an adja- 
cent filament, while its neighbor on each side had resorted to par- 
thenogenesis. Although several slides were examined, no cases of 
lateral conjugation were observed. : 
Fic. 2 
Abnormal conjugation in other species of Spirogyra has been 
mentioned by several investigators, notably by the Wests,’? who 
have examined material from many different countries. Several 
types of scalariform conjugation between three cells have been 
described: (a) by means of four branches connecting three cells 
belonging to two different filaments; (b) by means of four branches 
connecting three cells belonging to as many different filaments, 
(c) by means of three branches forming a triple connection. Accord- 
ing to the Wests the last type mentioned is very rare. They 
illustrate a case of triple connection of conjugation branches in 
S. condensata in which one of the three branches has prevented the 
*West, W. and G. S., Observations on the Conjugatae. Ann. Botany 
12:29-58. 1898. 
