202 REPORT OF COMMISSIONERS OF IXLAND FISHERIES. 



or Maine lobster of the male sex which has attained the length of 11 

 inches, is in the neighborhood of 8 years old. and that the female lob- 

 ,ster of this size is perhaps 11 or 12 years old. 



If, however, we still accept 15.3 per cent, as the actual rate of in- 

 crease in length for the earlier stages alone (as Herrick does), and. 

 on the other hand (assuming that 28 mm. (1^ inches) as ascertained 

 by Herrick, represents about the average size of the tenth stage 

 Woods Hole lobsters), make allowance for the diminution which we 

 know takes place in the rate of increase beyond the eighteenth stage, 

 we arrive at the sojiiewhat absurd conclusion that the Woods Hole 

 lobsters of the male sex and 11 inches in length can be no less than 

 15 or 16 years old! .Very apparently there is some flaw in our reason- 

 ing. Either Herrick started his experiments with undersized eggs 

 (very improbable), or the normal rate of growth for Woods Hole 

 lobsters, under natural conditions, is for some reason far greater than 

 that deduced by Herrick from the study of his young lobsters con- 

 fined in glass jars (very probable) . or we have not correctly estimated 

 the number of molts which (up to the twenty-sixth stage) occur 

 within the length of time specified in Table No. 18 (improbable). 

 There can be little doubt that the discrepancy lies in the second of 

 the above mentioned hj'potheses, namely, that 15.3 per cent, does not 

 accurately represent the average rate of increase in length for lobsters 

 in the first 18 stages, under natural conditions at Woods Hole; fur- 

 thermore, that certainly 15.3 per cent, is an overestimate of the 

 average rate of increase for lobsters past the eighteenth stage, in 

 whatever locality they may be. The fact may here be emphasized 

 that the most accurate possible data on the rate of growth of the 

 lobster for the first 12 or 14 stages is absolutely necessary for any correct 

 estimate of the size and age of adult lobsters; for it is upon these first 

 stages, so quickly passed, that the influences of which we have been 

 speaking have their greatest, perhaps their only, effect. Such data 

 we now, for the first time, have in hand, and, as we have already 

 shown, the rate of increase for Wickford lobsters in these earlier 

 stages amounts to 18.4 per cent. 



