THE NAUTILUS. 23 



animals were placed in an enclosure, and were fed for several 

 weeks. Preliminary steps in the reproductive process (the so- 

 called Liebspiel) were noted on several occasions, but evidently 

 complete union never took place since no young were produced. 

 More definite information, therefore, was sought in the field, 

 but conjugation evidently takes place at night since on two 

 days only and those dark and gloomy in the early morning- 

 was the act witnessed. 



Prior to the act of conjugation each individual viciously bites 

 the side of its mate (faced in the opposite direction), then 

 violently retracts the head which gradually is protruded before 

 the next onslaught. The intensity of this first phase gradually 

 lessens as the bodies become curved about each other, thus 

 finally bringing the genital papillae in contact. The penis of 

 one individual only is then inserted, and after a period of several 

 hours the two animals commence to draw apart. In both of 

 the observed cases, when the penis had become exposed to the 

 extent of about half an inch, one of the animals turned its head 

 and commenced to gnaw upon the walls of the organ. These 

 biting movements were unusually vigorous, and therefore in 

 marked contrast to those witnessed during the feeding process 

 but practically identical with those in the initial stages of con- 

 jugation, and within ten minutes had so scotched the penial 

 walls that the exposed portion had stretched to an inch in 

 length. The other animal (subsequent dissection in one case 

 showed it to be the possessor of the intromittent organ con- 

 cerned) now took part in the process, and within a very few 

 minutes the penis was entirely severed. 



All four of the animals were subsequently killed and dissected. 

 In two of the individuals the gnawed-off penis extended from 

 the genital pore through the proximal section of the oviduct to 

 the distal, blind end of the seminal receptacle. The walls of 

 the oviduct were in a high state of contraction, and only with 

 the greatest care was it possible to dissect out the penis without 

 destroying the surrounding tissue. In the other two specimens 

 the penis was wholly absent, and the vas-deferens extended to 

 to the genital pore a condition of affairs exactly duplicated in 

 some of the other animals examined on previous occasions in 



