





V 



19 1 7] CUNNINGHAM 



RA 495 



twisting 



In each case, however, 



he has retained all the cells, whether conjugating or not, from the 



conjugatin 



When 



more filaments 



parallel also, and as nearly as possible in their relative position. 



method 



may grasp more 



em 



Diagram 



matic drawings can be followed more readily than the windings 



camera drawing, as may 



i 



pi. XXIV, with fig. i, pi. XXV. The former is a microphotograph 

 of a portion of the pair of conjugating filaments schematically 

 represented in the latter. Furthermore, the diagrammatic method 



consumes 



exhibited at the meeting of the North 



Carolina Academy of Science in May 191 5, where they were 

 observed by a number of botanists. Other slides were sent to 



* 



1 flat a 



Sp 



membrane 



the ends. The length of the vegetative cell is about 80 ju. and the 

 width about 15 /jl. The zygote cell is swollen on both sides. The 

 zygote length is about 43 11 and the width about 28 /*; zygote 

 oval, considerably pointed, brown at maturity. In these characters 



it follows closely the descriptions for Spirogyra inflata. On the 

 other hand, it is to be noted that the connecting tubes are always 

 put out by the male cell and fuse directly with the cell wall of the 

 female cell. This is true regardless of which filament furnishes the 

 male gamete, and would indicate that the sex character was . 

 present even before the conjugation tube was put forth. 



This species differs also from S. inflata in the phenomenon of 

 cross-conjugation, which has not been ascribed to it by any modern 

 work available to the writer. Lotsy (23, p. 198) states that there 

 is a difference between the male and female filaments of S. inflata, 

 which can signify scalariform conjugation only. Wolle (31) asserts 

 that conjugation may be either lateral or scalariform. DeToxi 

 (12, p. 766) gives Conjugnee renflee of Vaucher (citing Vaucher, 



