186 



IOWA ACADEMY OF SCIENCE Vol. XXV, 1918 



the following- were found : Cast spiderling skins, 195 ; dead 

 spiderlings, 17 ; live spiderlings, 13 ; quiescent spiderlings, 32 ; 

 developing eggs, 18 ; unfertilized eggs, 15. At the time the 

 cocoon was examined 5 spiderlings had emerged. Such an ex- 

 amination throws much light upon Avliat must take place in this 



F^G. 35. — Third stage of cocooning process, finishing the cocoon. In this 

 drawing the female is worliing together the strands of silk with her jaws, 

 or chelicerae. Drawing X4. 



closed bassinet. The presence of 195 cast skins shows that the 

 first molt takes place inside of the cocoon. This is also shown by 

 the presence of the quiescent nymphs which are known to be the 

 first instar. The presence of 17 dead spiderlings and of so few 

 live ones in proportion to the large number of cast skins found 



