\\VMAX REED GREEN. 



this position he waved his abdomen about for a few seconds, 

 then straightening it, he ejected the spermatozoa in two forcible 

 streams, which, like puffs of smoke, spread abruptly when their 

 force was spent. They seemed to me to be all swept away by 

 the exhalant respiratory current of the female. The excitement 

 of the males was now abated, and in about fifteen minutes I 

 removed the males. Two hours later I introduced the males 

 again and secured a second mating. In this instance the male 

 ejected the spermatozoa just anterior to the posterior end of 

 the abdomen of the female, and posterior to her last pair of 

 appendages. Again I saw some of the sperm cells swept away, 

 but very few. I am now convinced that the first case described 

 was abortive. Other observations \vere made later and in some 

 cases no part of the mass of spermatozoa was lost, though no 

 case was observed in which the sperm cells were not ejected freely 

 into the respiratory chamber as described, the only point of 

 contact being the ventral margins of the male's carapace with 

 the antero-ventral margin of one side of that of the female. 

 The ephippial egg is laid within about an hour, and in no case 

 observed more than two hours, after the pairing. During the 

 period of oestruation the female doubtless produces some chemi- 

 cal substance which passes out in her exhalent respiratory cur- 

 rent, since it is by passing through this that the males are made 

 aware of the females' readiness to mate. 



I have made oft repeated attempts to observe the copulation 

 process from the lateral aspect. Several devices, such as a 

 trough made of cover glasses and a slide, in which the specimens 

 were placed, yielded only failures. The males do not always 

 attach to the same side- of the female's carapace. In case the 

 male attaches himself to the left side of the female's carapace, 

 the spermatozoa are ejected near that side ol the respiratory 

 chamber and pass to the left of her abdomen to the brood pouch. 

 seemingly being driven dorsad by the action ot her last pair ol 

 appendages. In one such case observed the ephippial egg was 

 developed in the right ovary. In order to enter the oviduct 

 tin- spermatozoa would have to pass across the brood pouch to 

 ihc right side. The sperm cells are immotile. Though I 

 have not yet been able to see them after they have been trans- 



