NATURAL HISTORY SOCIETY OF GLASGOW. 9 



excessively, and at the same time the Lily appeared to suffer 

 more and more. 



Seeing that the plant was perishing, and that whatever ex- 

 periments he might make to remove these pests in hope to give 

 the plant a chance of life, he could not be chargeable with its 

 destruction even should it die, he applied a little lime to the water 

 in the tank, and in a very short time the insects had almost 

 entirely disappeared. 



The plant, thus freed of its enemies, began at once to improve 

 and regain its usual health. 



It may be asked upon what do these animals live ? According 

 to Midler and Straus, the greater number of Entomostraca, if not 

 parasitical, live on vegetable matter. Dr Baird calls this in 

 question, and asserts from observation that the Cyprididse in 

 particular seem to be most voraciously carnivorous, but this in no 

 way affects the question, as these holes or burrows are obviously 

 not made for food, but as a shelter and nidus to their young. 



If the increasing size of the holes were made by being nibbled 

 away mechanically, we might expect to find some part at least 

 of the abrasion raw, which close inspection failed to detect, but, 

 on the contrary, the enlarging holes were surrounded by gangrenous- 

 looking edges, which appeared to go on spreading from the first 

 injured point. 



This little Crustacean, Cypris Icevis, is not uncommon in ditches 

 and small patches of water, but I never saw them in such abundance 

 in exposed situations as in the warm tank, which no doubt tends 

 greatly to increase their numbers. 



In a hot-house at Millport, in a barrel kept with water for the 

 plants, I found another Ostracod of the same genus in abundance, 

 Cypris incongruens (Ramdohr). In another barrel outside the 

 same building the same species was found, but not one for 

 twenty that were in the barrel within the house, which was much 

 warmer. Both these vessels were supplied with water from the 

 same source, and that there were more Ostracoda of the same 

 species in the one vessel than the other, I can only ascribe to the 

 additional heat. 



There can be little doubt, if any, that in this case and most 

 others these animals get in with the supply of water through the 

 pipes. This suggests a remedy to prevent their entrance, which is, 

 to let the water pass into the tanks through a sieve sufficiently 



