REPORT OF COMMISSIONERS OF INLAND FISHERIES. 101 



■would more nearly approach the normal size at the first moult. This 

 suggests an explanation of Brooks's results. From an examination 

 of his data it appears that the lobster which he cites had lost the am- 

 bulatory limbs in question during the winter (the exact date is not 

 given) ; consequently the new leg had a comparatively long period 

 to regenerate before the next ecdysis in the spring, and so attained 

 more nearly the normal proportions at the first moult. 



If the thoracic appendages then do not attain the normal length at 

 the first moult the ciuestion which next arises is: How long does it 

 take a regenerating appendage to attain the normal size? Of course this 

 ciuestion must be answered in terms of moulting periods rather than 

 in terms of days and months, because the rapidity of regeneration, 

 like the frequency of moulting, varies with the age of the lobster. 



There is a popular belief that a lobster's appendages will be re- 

 stored to normal length in one or at least two moults. The present 

 observations, however, do not seem to justify such an opinion. In all 

 the data there was no exception to the following observations: 

 neither the antennae, maxillepeds, thoracic appendages, the first 

 pair of abdominal appendages (accessory reproductive organs), nor 

 the swimmerets attained normal length at the first moult. In re- 

 gard to the second moult a difficulty was encountered through the 

 fact that in the mature lobster only one moult usually occurred during 

 the summer. In the few cases in which data were obtained on the 

 chelipeds through the second moult, those limbs had not yet grown 

 to normal length. Fig. II, Plate XXI, is a good illustration of the 

 comparative size of the regenerated and normal chelipeds just after 

 the first moult. Figs. I and II on the same plate also show the re- 

 markable expansion which occurs in the regenerating structure as 

 soon as it is released through the moulting process from the mem- 

 braneous sac of the bud. 



This difficulty, arising from a long interval between the moulting 

 periods, disappears in case of experiments wath very young lobsters. 

 The right chelipeds of lobsters varying from the fourth to the ninth 

 stages were removed and the regenerating structures compared 



