THE OYSTER A SOCIAL ANIMAL. 



693 



or hearing, the sense of touch is all that it has, and this resides 

 in the tentacles of the mouth. Its taste, if it has any, must 

 be very feeble. Its powers *\re most limited; imprisoned for- 

 ever in its shell, it has no power of locomotion, and being 

 without any distinction of sex, its wants or desires must be 

 very few. 



Still the oyster appears to be a social animal, and loves to 

 gather together in great numbers, so that despite their appa- 

 rently low grade of intelligence, we cannot say that they have 

 not sympathetic feelings. Uniting as they do both sexes in 

 each individual, the oyster's organs of reproduction are visi- 

 ble only at the period they are in use. Their young are pro- 

 duced from eggs, which are produced between the folds of their 

 mantle, and in the midst of their respiratory organs. The 

 number of these eggs is prodigious. According to some au- 

 thorities the number produced by a single oyster reaches 

 10,000,000. Naturalists, however, at present consider this 

 estimate too high, and limit it at about 2,000,000 for each in- 

 dividual. The eggs are yellow, are hatched in the mantle, and 

 when the embryo leaves its parent it can breathe. The spawn 

 ing time is from June to September. The oyster differs from 

 most shell -fish in that when the young leave the parent they 

 can support themselves; ordinarily the shell-fish throw out 

 their eggs committing them to chance for their protection. In 

 the spawning season an oyster bed is the most interesting 

 place ; each oyster is throwing out a whole army of descend- 

 ants, filling the water with a cloud of living dust, so that the 

 sea is clouded with the spat as it is called. 



Under the microscope the spat is seen to be provided with 

 a shell, and with vibratory cils which enable it to swim. 

 When the current carries it against any stationary body, it im- 

 mediately adheres to it, the cils disappear and the young oys- 

 ter, becoming fixed, commences to develop. It takes three 

 years for f hem to attain their full size While the spat ia 



