1909.] NATURAL SCIENCES OF PHILADELPHIA. 549 



the free surface of the drop, but against the reverse surface of the 

 sheeting. At 5.43 he was interrupted by a feeding female, and he 

 moved away from the sperm-bridge with a minute droplet of sperm 

 at the apex of his right palpus and another left on the bridge. Another 

 d\ No. 1508, of the same species, copulated on 17 June, and the day 

 following was observed at the close of the sperm-induction at 7.10 P.M. ; 

 he had spun from one vertical wall of the cage to the other, in an angle, 

 a narrow transverse ribbon of silk, with its flattened surface in the 

 vertical plane; against this he placed his ventral surface, with his 

 cephalic end elevated and the abdomen flexed, applying his palpi 

 gently and alternately against that surface of the sperm-bridge directed 

 away from his body. He ceased at 7.15, went into a corner of the 

 cage and there rested quietly. With a hand lens a thin film of sperm 

 could be seen upon the bridge, and next day the sperm was found 

 with the aid of the compound microscope. The same male (1508) 

 copulated on 20 June in the morning, and at 6.20 P.M. was found 

 forming another sperm-bridge like the first; at 6.24 he dropped a 

 minute globule of sperm upon it, and then applied his palpi in alterna- 

 tion to it as in the preceding cases ; this palpal application lasted six 

 minutes, when he turned away, but he seemed to be prematurely 

 interrupted by the movements of a grasshopper. 



The other case was that of a male of Drassus neglectus (Keys.), 

 No. 1527. He and a 9 , No. 1528, were caught together in a closed 

 nest on 17 June, placed in a cage, and there he built a beautiful and 

 spacious saccular nest around both. On 23 June, at 11.37 A.M., he was 

 observed in nearly vertical position within this nest, moving the 

 ventral surface of his abdomen repeatedly against an inclined sperm 

 bridge built against the inner surface of the nest and with its upper 

 edge free. In half a minute he discharged a droplet of sperm upon it, 

 then lowered his body to bring his jaws about on a level with the upper 

 margin of the bridge, reached his palpi over this free margin and rubbed 

 them gently many times against the reverse side of the sperm-bridge. 

 One palpal bulb was thus rubbed at a time, then raised in the air 

 while the other was rubbed. The application of the palpi continued 

 for 17 minutes. 



In all the cases so far described there is quite general uniformity 

 in the process of sperm-induction; a special sperm-bridge is spun, a 

 droplet of sperm placed upon it on the side next the spider's body, 

 then the palpi applied alternately against the opposite side. The 

 cephalothoracal end is always raised. In the case of Phidippus, 

 No. 1508, this act was seen twice, each time after observed copulation, 



