160 UTILIZATION OF MINUTE LIFE. 



sented for Madras as 34,184, and for Calcutta, 

 29,985.* 



Sir Emerson Tennant has given an account of 

 this shell, under the name of Turbinella rapa. 



In a preceding chapter I mentioned the curious 

 manner in which lost or mutilated organs are re- 

 generated or replaced in inferior animals, and even 

 in some of the higher classes. This regenerative 

 faculty is very remarkable in snails, and Mollusca in 

 general. When a snail's shell is broken, the animal 

 repairs it in an astonishing manner; and when 

 some part of the animal's body has been cut away, 

 it also reappears. Spallanzani, having cut off a 

 snail's horn, observed that it began to bud out 

 again in about five and twenty days, and continued 

 to grow until it was as long as the other. He then 

 cut away part of the head of another snail, and in 

 course of time the lost portion was renewed. When 

 the head was cut completely off the experiment 

 sometimes failed, and the animal died; but more 

 than once a new head grew again even in this case ; 

 at the end of a few months the snail appeared with 

 another head, in every respect similar to the lost 

 one. The snails thus operated upon retired into 

 their shells the moment decapitation had taken 

 place, and covering the opening with their oper- 

 culum, remained thus enclosed for weeks, and even 

 * See "The Technologist," vol. ii. (1862), p. 185. 



