162 Forty- fifth Report on the State Museum. 



although flies and other insects, and small earth worms were offered it. 

 It underwent no moul tings or other changes, and at the expiration of 

 the time stated, it died, apparently from not having partaken of 

 nourishment. 



Professor Riley has written (in the Canadian Entomologist, as 

 cited) of the respiration of this larva as follows: "In the water a con- 

 stant motion of the ventral branchial tufts is kept up, the main stem 

 being first moved quickly backward and upward so as to bring the whole 

 tuft close to the body, the filaments of which it is composed being then 

 closely appressed to each other. The main stem is then brought more 

 slowly down in the opposite direction, when the filaments spread and 

 enlarge the whole to its utmost. In pure water the motion occurs about 

 once a second; as the water becomes impure the motion becomes 

 more rapid." 



The respiration as observed by me, not long after its reception and 

 therefore before it could have become enfeebled, was far from being con- 

 tinuous, — on the contrary it was remarkably intermittent, without any 

 apparent cause. The following note was made at the time: 



The branchial tufts may be, and frequently are, used independently 

 of one another. The first and second pairs on segments four and five 

 are the most frequently used, and sometimes those only on one side 

 are in action. An interval of twelve seconds has been observed, 

 without the slighest branchial motion. Occasionally, the only respira- 

 tion seen was in the movement of a single branchial tuft. When 

 transferred to fresh water the respiration was increased in rapidity, 

 fifty-two motions having been counted in a minute. 



Professor Riley has written: " The motion of the larva is invariably 

 backward." During its confinement in the aquarium, my specimen 

 was often seen to swim iu a forward direction, almost completing the 

 circuit of the vessel, and with a facility very nearly equaling that of 

 its ordinary mode of progression. 



