On some South-AMcan Phyllopoda. 15 



proceedings for rather a long time. But it appeared that 

 the number of specimens was at last diminishing in a 

 suspicious manner, though no disease whatever could be 

 observed in those which at times came up to the surface 

 to seize the food. A closer examination of the aquarium 

 at once revealed the cause of this strange decrease of 

 specimens. Not content with the vegetable food, which 

 they had in abundance, they were impelled by their voracious 

 nature to attack each other, and on the bottom of the 

 aquarium the mutilated bodies of several specimens were 

 found, some of which still showed signs of life, though the 

 greater number of the legs had been torn off by their 

 companions. Two of the specimens a male and a female, 

 were now placed in another aquarium arranged with great 

 care, and, as a rather rich supply of food, consisting both 

 of smaller Entomostraca and vegetable fragments, was con- 

 stantly thrown into it, I hoped that at least these two 

 specimens would live in good terms with each other, and 

 perhaps give rise to a new generation. But this attempt 

 also failed of success. The love of the male assumed at 

 last a very brutal character, and one day it was seen carry- 

 ing the body of the female between its legs in a very 

 pitiful condition, most of the soft parts having been torn 

 off by her cannibal mate. At last only 2 specimens, a male 

 and a female, remained 1 ). These I placed in 2 separate 

 aquaria, both richly supplied with food, in order to watch 

 their growth as long as possible. I had them living until 

 the close of August, their age being estimated to be about 

 3 months. As at that time they seemed to have attained 



x ) 8ome few specimens were, however, at an earlier period secured 

 for the sake of anatomical examination. 



