42 



TABLE IX.— LOBSTER. 



The male evidently casts more frequently, but during the 

 years of actual experiment it does not gain thereby an increase 

 in size over the female. The later stages of the female are known 

 from actual observation to have instars of several years. And 

 in this case it has been observed that a female may come into 

 berry twice in the same instar. It has not happened in our 

 experience, although we have for manj^ years kept berried females 

 until hatching took place, and in the majority of cases until the 

 ecdysis. But Cunningham and Andrew Scott have recorded 

 cases. It may occur therefore during the later stages when more 

 than two years intervene between ecdyses. 



Some information as to the growth of the Norway lobster, 

 Nephrops norvegicus, may be derived from Storrow's account 

 in the Report for 1911 (new series I.) Females with newly spawned 

 eggs were got mostly from Juty to October, the largest number 

 in September. Hatching was found to take place from May to 

 September, but for the most part in June. This points, as 

 Storrow states, to an incubation of about nine months , The four 

 zoea stages are similar to those of the lobster. 



Females become mature at a size of 8 cm., more at 11-14 cm., 

 and are caught to a size of 17 cm. ; males mature at 10 cm., and 

 are found to a size of 22 cm. or slightly more. Males were found 

 to be mature ail the year, but the obvious signs of active maturity 

 were mostly evident in August. This, or say July-October, is 



