REPORT OF COMMISSIONERS OP INLAND FISHERIES. 51 



before again resuming their activities. Although the young lobsters 

 for the most part swim while eating, many times the process is carried 

 on while they are lying on their side or back at the bottom. In the 

 above case, however, there was no food of any kind in the jar and 

 not any trace of masticatory activity evinced. When placed in 

 other jars containing food, the third stage lobsters manifested more 

 perseverance in action than was noted in any preceding stage. 

 Many times an individual lobster would make three or more succes- 

 sive attempts to secure food lost in the first grapple. While swim- 

 ming near the bottom there were many times apparent efforts to come 

 to rest in an upright position and to support the body by the large 

 claws, but these efforts seldom were successful, and unless active 

 swimming was kept up, an upright position on the bottom could not 

 be maintained. 



In the third stage the second, third, fourth, and fifth abdominal 

 segments possess swimmerets differing in no way from those of the 

 previous stage, save that now they are bordered with a delicate fringe 

 of setse. The last abdominal segment has undergone a decided 

 change since the foregoing stage. A pair of appendages has developed 

 on either side, each consisting of an endopodite and exopodite, re- 

 spectively. (Plate XVII.) These are bordered with setse and greatly 

 increase the tail surface upon which depends so greatly the lobster's 

 ability, in later stages, to dart with a single stroke of its tail back- 

 ward through a remarkable distance. There are still no traces of 

 appendages upon the first abdominal segment. 



The Fourth Larval Stage. 



When for a third time the young lobster has cast his moult, there 

 emerges an animal which is very different from the third stage and 

 which resembles very nearly the form of the adult lobster. This ap- 

 pearance so suddenly created is clue to many changes which will be 

 considered in detail. 



In the general body form there has occurred a marked straightening 

 and elongation, the rostrum having developed a number of spines 



