CONJUGATION IN PARAMECIUM 
287 
jugated March 9). This lot was known as M. These conjugated 
among themselves May 11, and a single member of one of the 
pairs was isolated, and allowed to multiply; it was designated 
kha. Among its progeny conjugation occurred again May 24, 
kb 25 pairs kh kha khaa khaaa 
Nov. 9 Mar. 9 May 11 May 24 Jan. 29 
Fie:. 3 Diagram showing the conjugations in the pedigree of khaaa. The 
fissions intervening between the conjugations are omitted. 
and one member of a pair was again isolated after separation, 
receiving the designation khaa. This multipUed, lived through 
the summer and fall, underwent repeated epidemics of conju- 
gation, and the chain of observation could be taken up again only 
in January, 1910. On January 29, a new conjugation occurred, 
and the single member of a pair khaaa was isolated. The culture 
khaa (fourth generation of inbreeding) is still flourishing; while 
prosperous beginnings of a culture are on hand descended from 
the single individual khaaa isolated from the fifth conjugation 
in series. 2 
The pedigree of the Hne just described may be represented by 
the diagram of fig. 3. 
2 This series has been continued, so that at the present time (Oct. 2, 1910) 
there have been nine conjugations in succession, all the conjugants at each 
mating being progeny of a single ex-conjugant from the previous mating. 
(Note added at correction of proof.) 
