382 Proceedings of the 'Royal Physical Society. 



dage was liberated at ecdysis four months after loss. He 

 also gives a figure of the coiled rudiment. 



With regard to the chelae, my observations afford precise 

 data in three instances, which are as follows : 



Lobster A. 



1. Both clielffi lost 5, iii. 83 ; reproduced at ecdysis, 25, viii. 83 ; 



interval about 5^ mouths. 

 Lobster 0. 



2. Left lost 7, xii. 82 ; ) ,,-. „^,,„„i , ^ i •• co ^ interval 7 rnos. 

 Right,, ^^it. 83;P^^^^^^P^^^^^«^l'^'^i-^3-=i „ 5 „ 



3. Both ,, 14, viii. 83 ; both reproduced 25, xii. 83; ,, i „ 



It will be noted that in examples Nos. 1 and 2 the chelae 

 were lost between December and March, that is, at a time 

 when the temperature is low. In these cases the interval 

 was long, averaging nearly six months. In the third 

 example the chelae were lost in the summer, and were re- 

 produced four months afterwards. The lobster, unlike the 

 crayfish, does not appear to refuse food during any definite 

 period of the year, and, so far as my observations go, only 

 does so for a short time prior to each ecdysis. There does 

 not, therefore, appear to be an alternation of periods of 

 growth and rest as in the crayfish, or, at any rate, these 

 periods are not so well marked. Nevertheless ecdysis ap- 

 pears normally to take place during the spring and autumn, 

 and the two instances here recorded during November and 

 December may have been due to the fact that the specimen 

 was kept in confinement and at a temperature above that of 

 the sea. Perhaps the information I have on this point is too 

 meagre to allow of general deductions, yet, so far as it goes, 

 it tends to show that limbs lost in the summer are reproduced 

 more rapidly than those lost in the winter. Should this 

 prove to be the case, the fact may depend partly on tem- 

 perature and partly on food supply. 



Deposition of Pigment in New Appendages. 



All rudimentary appendages in the lobster appear to be 

 pallid white in colour when first formed. After a time the 

 rudiment becomes tinged with pink ; the pink then becomes 

 deeper and deeper, until a deep blood-red tint is obtained. 



