318 NATURE-STUDY REVIEW [10:8— Nov., 1914 



On the narrow end of the aquarium we discovered a number of 

 little, jelly-like masses, which Professor Parker told us were the 

 eggs of the Physa snail. They were nearly an inch in length 

 and very narrow. Each mass contained a large number of eggs. 

 By the aid of a magnifying glass we counted the eggs in three 

 masses, and found one hundred and thirty in one, one hundred 

 and sixty in another, and two hundred in the third. The Profes- 

 sor placed one of these masses under the microscope, and we 

 observed the little embryos slowly rotating about. 



"The eggs of the fresh-water snails," said the Professor, may be 

 found any time during April or May. The young hatch out in 

 June. They are transparent little animals, about one-fiftieth 

 of an inch in length. They are very active, and eat voraciously 

 of anything which they find. Some of the water-breathers 

 lay but a single egg, which is inclosed in a round capsule. The 

 young of the apple snails are born alive, and are minute, trans- 

 parent animals, about one-eighth of an inch in length; they are 

 very active. 



Near the aquarium, the Professor had a snailery in which were 

 several dozen snails of various species. The snailery was made of 

 an aquarium about the size of the one in which the fresh-water 

 snails and clams lived; the bottom was covered with earth to a 

 depth of three or four inches, and a little pan of water was sunk in 

 one comer to imitate a lake ; several ferns were growing in the op- 

 posite end ; a piece of netting was stretched over the top to keep 

 the snails from escaping. 



A snail was crawling over the moist earth, and we watched to 

 see what it would do. It was evidently headed toward a fresh 

 piece of lettuce leaf, which had been recently placed within. The 

 snail went along slowly, moving its eye peduncles about nervously 

 and retracting them when they came in contact with a lump of 

 earth. Occasionally it would raise its head until it rested only up- 

 on the last third of its foot, and then, it would twist about its head 

 and eye peduncles as though it scented danger. 



In a little while the lettuce leaf was reached. Resting upon the 

 hind part of its foot, it raised the fore part and began to bite off 

 pieces of the leaf. We could see the homy jaw come out of the 

 mouth, bite off a piece of lettuce, and then swallow it, accompany- 

 ing the action by a faint rasping sound. Professor Parker told us 



