l6'Z AMPHIMIXIS OR ESSENTIAL MEANING OF [XII. 



placed a solitary individual in a small aquarium, and allowed it 

 to multiply until the whole vessel was full of mature, egg- 

 producing descendants. All the individuals of the colony were 

 then passed in review, and the greater number were killed and 

 preserved, one or more having been selected for breeding, and 

 these were placed separately in fresh aquaria. In this way, 

 in the course of seven years, many thousand individuals have 

 passed through my hands ; for the animals breed very rapidly 

 and at all times of the year. 



A B 



Fig. X. 



Cypris reptans, Varieties A and B. 



The first and most remarkable result is the fact that the de- 

 scendants of any one individual bear a very close resemblance to each 

 other and to their ancestor. I was not able to find any individuals 

 which were precisely alike, although at first sight it often 

 seemed that such was the case : minute differences, however, 

 invariably existed as far as my observations reached, although 

 they were often so small as to lead to the doubt whether they 

 were due to different predispositions or to different nutriment, 

 etc. And indeed no two.individuals, not even ' identical ' human 



£ 



