18 Bulletin Wisconsin Natural History Society. [Vol. 0, Xos. 1-2. 



first loosened at the lips, and then rolled backward, aided by loco- 

 motor movements of the animal ; the cuticle of the feet comes off 

 like a glove. 



In A. jeffersonianum and A. punctatum the cuticle was usually 

 broken into two or three pieces. The process of shedding, 

 observed when just begun, was found complete 2-3 hours later. 

 Each specimen evidently sheds the cuticle at intervals of a few 

 days. 



When handled, individuals of both A. jeffersonianum and A. 

 punctatum often become immovable. Two one-year-old speci- 

 mens of A. punctatum (see Plate 2, Fig. 3), active when cap- 

 tured, were brought to the laboratory and placed in water in a 

 finger-bowl at room temperature ; so far as could be judged from 

 repeated though not continuous observation, they kept the same 

 position for 24 hours. When first handled at the expiration of 

 this time, they were thought to be dead ; after being handled for 

 several minutes, they slowly showed signs of life and normal 

 activity. Perhaps this was a "death feint" or hypnotic state. 



By daylight, in the aquaria, A. jeffersonianum was more active 

 than A. punctatum. When watched at night by electric light.A 

 punctatum was more active, seemingly in efforts to escape. 



In captivity both species will eat earthworms. A. jeffersonia- 

 num will eat readily even when newly captured ; recently captured 

 specimens of A. punctatum refused this food. 



SPERMATOPHORES, AND THE TIME OF FERTILIZATION 



The distribution and structure of the spermatophores of A. 

 punctatum have already been adequately described (Smith '07 and 

 '10), except for the trifling correction that the spermatophores 

 are sometimes deposited on a vertical as well as a horizontal sur- 

 face. The breeding behavior of A. punctatum has been described 

 by Wright and Allen ('09). 



The deposition of spermatophores by A. punctatum precedes 

 egg-laying by several days. In 1909 the first spermatophores 

 were found on April 5, the first eggs of A. punctatum on April 13. 



In Branchipus Pond all the spermatophores studied were 

 identified as belonging to A. punctatum. In ponds inhabited by 

 A. tigrinum I have been unable to find spermatophores of Amby- 

 stoma; observations have been confined to the spring. The ex- 

 tremely early spawning season of A. jeffersonianum and A. 



