Zool— Vol. I.] RITTEli—DIEMYCTYLUS TOROSUS. IOI 



or chains that may by chance be in the water, posts, etc., 

 are made use of at times. 



In streams, quiet pools and places overhung by the banks 

 are usually selected for the eggs, but in the reservoir, which 

 is merely a great basin with sloping sides, and in which but 

 few foreign object are contained, they are often attached to 

 any weed or stick that may chance to be found, even though 

 these be in shallow water and fully exposed to sight and to 

 the light of day. 



In one or two instances I have found bunches of eggs, 

 laid by females kept in the laboratory, that were not attached 

 to anything, but were loose on the bottom of the aquarium. 



In laying her eggs the female clasps the stick or other 

 object to which they are to be attached, not so much by en- 

 circling it with her hind limbs as by grasping it between her 

 feet. This position enables her to easily lift her cloaca some- 

 what from the object as the egg mass is being extruded. I 

 have not actually observed her to thus raise herself, but infer 

 that she does so from the fact that as a rule the egg masses 

 do not depart much from the spherical form, and it is diffi- 

 cult to see how this could be so were the cloaca to be held 

 closely pressed to the object to which the eggs are attached 

 throughout the process of their deposition. 



The bunches frequently have a low, flat, conical projec- 

 tion on the side opposite, or nearly opposite, the point of 

 attachment. This is shown in fig. 12. 



One frequently observes numerous alternating grooves 

 and ridges on the surface of the gelatin, and not infrequently 

 these converge toward the cone. It seems as though the 

 cone is the last portion of the mass to leave the cloaca, and 

 that it is produced by a slight clinging of the gelatin to the 

 cloaca after the egg mass proper has escaped; and for this 

 reason we may speak of the cone as a hilum. The ridges 

 above mentioned are probably the result of pressure of the 

 jelly mass against the walls of the cloaca, although of this 

 I am not fully convinced, since occasionally they are seen 

 to converge toward more than one center on the surface of 



