Conjugation and Rate of Reproduction 145 



emphasize this point, for upon it an extraordinary error has 

 become widespread even among expert biologists. 3 



Maupas rejected emphatically the idea that aging shows 

 itself in a decrease of the rate of reproduction and that 

 conjugation restores this declining rate. He asserted posi- 

 tively that no such decline occurred before conjugation and 

 that after conjugation reproduction was not more rapid 

 than before, and he based these statements on the results of 

 careful experimentation. Richard Hertwig's experiments 

 led to the same result and induced him to subscribe com- 

 pletely to Maupas' assertions on this point. The matter is 

 important, since the doctrine that conjugation restores the 

 declining fission rate depends largely on their supposed sup- 

 port of it. I therefore give in their own words statements 

 of the results of their experiments, and of the conclusions 

 they drew from these results. 



Maupas sums up the prevailing mistaken doctrine of his 

 time on this matter in words which well fit the present con- 

 ditions : 



"It has been affirmed that the faculty of reproducing by 

 fission in the ciliates was modified by conjugation, and that 

 the principal effect of this sexual act was to reenforce and 

 accelerate this reproduction. The ciliates, it was held, im- 

 mediately after conjugation multiply more rapidly than 

 they do at a later stage. This opinion has become current, 

 and one finds it reproduced in Memoirs and in general trea- 

 tises, as if it were a definitely established truth" (1888, p. 

 254-255). 



Maupas then proceeds to show that the evidence on which 



Thus, investigators so experienced as Woodruff and Erdmann in a 

 recent paper (1914) contrast my own results on this point with "the 

 view of Butschli, Maupas, Hertwig and others," asserting that accord- 

 ing to the latter, after mating "all the processes of the cell, including 

 reproduction, proceed with greater vigor." 



