REPORT OF COMMISSIONERS OF INLAND FISHERIES. 187 



probably determined more by the directive influence of the light rays 

 than ]:)y the light intensity. 



Second Larval Stage. 



Unlike the first-stage larvae just after hatching, the second-stage 

 larvjie, just after molting, were found to be more freciuently negative 

 than positive in their phototactic reaction. The negative photo- 

 tactic reaction, as in the case of the first -stage larvae, was maintained 

 until toward the last of the second stage-period. As the time of 

 molting to the third stage approached, the phototactic reaction 

 commonly changed again to positive. Throughout the second stage- 

 period the photopathic response, as was the case in the first stage- 

 period, remained positive. Generally speaking, the reactions of the 

 larvae of the second stage were not as definite and invariable as the 

 reactions of the first-stage larvae. In the second stage-period photo- 

 taxis still appeared to retain the dominating influence over the 

 behavior of the larvae; for they could be made at any time to move 

 from a region of less into a region of greater light intensity in order 

 to travel, in the direction of the rays, either to or from their source. 



Third-Stage Larvae. 



Regarding the behavior of the third-stage larvae, it is sufficient to 

 say that, in general, the reactions were similar to those of the second 

 stage. When newly molted from the second stage, these lobsters 

 commonly manifested a negative phototactic reaction, and this 

 reaction endured until toward the end of the third stage-period. 

 Then the reaction usually became definitely positive, even under 

 light of great intensity; and continued so until the larvae had again 

 molted and entered the fourth stage. During this third stage-period 

 the photopathic reactions, as was the rule for larvae in the first and 

 second stages, remained constantly positive. Thus it was again 

 demonstrated that, in certain periods of the larval stages at least, a 

 positive photopathic might accompany a negative phototactic 



