9 4 Th irtieth Annual Meeting 



EXPERIMENTS IN LOBSTER CULTURE. 



I?Y Dl{. \. D. :\IKA]). 



Tlicre is, in the lii'o of ilic lol)stL'rs, a dufiniti', well-marked 

 period lieginiiing when the eggs are hatehed and ending when the 

 young have shed tlieir shells thi'ee times and have reached the 

 fourth stage of development. During this period the young are 

 very poorly eqiupped, eitlier in structure or hal)its, for protecting 

 themselves against tlieir enemies or from escaping from them. 

 They swim ahout slowly and aimlessly in the water, an easy prey 

 to shrimps, fishes, and otiier animals ; they lack the hard shell, 

 the protective coloration, and the swift movements common to 

 most small Crustacea ; indeed, they do not have even the sense of 

 fear which might lead them to avoid danger. During this period 

 of life there is, as might readily he inferred, a very great mor- 

 tality. 



When, however, the skin has heen shed the third time and the 

 lohsters have entered the fourth stage, there is immediately an 

 ahnost miraculous change in their hahits and structure. In 

 many respects the difference hetween the fry in the third and 

 fourth stages is far greater than hetween animals helonging to 

 different orders, and the change may be compared to the meta- 

 morphosis of hying insects from their larval to their winged con- 

 dition. In the lobsters, however, the direction of the change is 

 the reverse of that in the insects. They tend to quit their swim- 

 ming habits, except for purpose of changing position, capturing 

 ])rey, etc., and 1)econie adapted to life on the bottom. They c-i-awl 

 over the bottom, hide under shells and sea-weed and, if these ob- 

 jects cannot be found, they even burrow in the sand. 



A brief statement of one experiment will illustrate tlu' sud- 

 denness of this changi' of habit. Three hundred specimens re- 

 cently nu)ulted into this stage were put into a car which had 

 gravel and stones in the bottom. Within ten minutes not a single 

 s])ecimen was in sight. 



Xot the least reiiiai-kable of the altered characteristics of the 

 fourth stage is their' mental attitude. Upon entering this stage 



