LOBSTERS. 93 



lime-salts from its envelope to enable that in places to become 

 slightly elastic (this can be seen very distinctly in the ecdysis 

 in the glass case). So soon as the exuviation is complete 

 the lobster then begins to pass back to its new coat the chemi- 

 cals absorbed from its old, and as the new shell is larger than 

 the old, the additional properties required to build up the 

 greater envelope are derived from broken bits of shells the 

 lobster swallows and retains as long as necessary, subsequently 

 regurgitating the unabsorbed portion. 



The smaller lobster I am exhibiting in the glass bottle, 

 you will notice, has many eggs attached to its abdomen. 

 Some are in a riper condition than others. The unaided eye 

 can detect the one from the other, and with the aid of a glass 

 an experienced person can see the eggs most ripe have been 

 extruded about two months, and according to Herrick's 

 and Fullarton's diagrams I should consider they were in the 

 eighth embryonic stage of development. 



When fully ripe, the eggs are oval in shape and measure 

 about 1-1 6th in. in their smallest diameter. This, as I have 

 already said, is about nine months after their extrusion. 

 As soon as the larva leaves the egg it swims up to the top of 

 the water and there remains as a pelagic free-swimming 

 creature until it has moulted six times. The animal's larval 

 and free-swimming existence continues altogether from six 

 to eight weeks (mainly according to the temperature of the 

 sea). At the end of that time it has grown to about fin. to 

 lin. long, and after the sixth moult it loses its power of swim- 

 ming, descends to the bottom, and there remains for the rest 

 of its life. 



It is just at the sixth stage of its existence, after its escape 

 from the egg, the beautiful and unique series of ecdysis Mr. 

 Waddington has kindly lent me begins. (See illustration.) 



This lobster was caught in a tow net in August, 1906 (I 

 believe off Bournemouth), showing it was then on the top of 

 the sea. On August 21st of that year it first moulted whilst in 

 Mr. Waddington's possession (but for the seventh time in its 

 existence) and grew Jin. It cast its shell again on September 



