NATURAL, HISTORY OK AMERICAN LOBSTER. 



359 



it would last 23 days, or a little over 3 weeks. Assuming that the bottom is not defin- 

 itively sought until the close of the fifth stage, the free swimming life at Woods Hole 

 would last 46 days, or a little over 6 weeks, and at Wickford about 30 days. 



Table ii. — ^Average Size and Duration op Stage Period in the First Eleven Stages. 



Assuming, further, that under natural conditions the molts are passed more rapidly, 

 and that the bottom is sought some time between the close of the fourth and of the fifth 

 stages, the pelagic life will be found to cover a period of from 3 to 4 weeks. 



•■Conditions which determine the rate of growth and the duration of stages. 



The length of the stage period or the period between molts from first to last depends 

 upon (i) intrinsic and (2) extrinsic causes. Among the intrinsic causes the following 

 must be considered: (a) Inherited characters or the individual constitution, which 

 gives a certain bent or direction to activities and limits their scope, and (6) acquired 

 characters, such as the loss of limbs, which is certain to retard the rate of growth of the 

 body as a whole by diverting energy to the regeneration of the lost parts. 



Thus if the fighting and preying instincts, dtip tn inhpritaprp are ^tm nir ^ er in larva. 

 A than in larva B, A will get more food, grow faster, molt sooner, and, its inherited cap - 

 ital being equal in all other respects , it will digtanrp B in ttip rarp ffftl T ^^^ start an d| 

 irring mishaps, forge ahead at everv step of the way. The earlv advantages gained 



b^ 



J^ are cumulative in their effects. The parable of the talents is applicable even to the 

 lobsters, and the lapj'prard in the race, though of the same age, may not attain one-half, 

 or even one-quarter, of the strength of its more strenuous rival, and will be fortunate 

 if it is not cut into pieces and dev oured, a contingenc y quite likely to happen when 

 its runninsf ma tes are cro wded or underted. " ^ 



Among the acquired characters are to be reckoned any weakness which may be due 

 in the first instance to congenital defects, such as imperfect or undersized eggs, acci- 

 dents like the loss of a limb, mutilations of any kind, which, as Emmel {90) has shown, 

 increase the stage period and therefore diminish the rate of growth, or parasitism which 

 may be encouraged by a lowered vitality or improper food. 



