2O8 FOOTE AND STROBELL. 



cocoon can be deposited by one worm alone, and our earlier 

 observation of the formation of cocoons during copulation, seems 

 to prove conclusively that there are two methods of forming 

 cocoons. These observations reconcile the opposing opinions l 

 on this point. 



That the deposition of cocoons by a single worm was not due 

 to isolation, we detei mined by finding, in pots containing one 



Slime tube.. Cocoon. 



FIG. I. X 3- Forty-two anterior segments of a worm with a cocoon in the process 

 of formation. The transparent slime-tube surrounds the worm from the tenth to the 

 thhty-sixth segment, and shows constrictions at each edge of the clitellum. The 

 white cocoon encircles the clitellum. When the worm was dropped into boiling water, 

 the cocoon became opaque effacing the segments of the clitellum. 



hundred worms, a number of single worms each with a cocoon 

 around the clitellum. During the summers of 1901 and 1902, we 

 found sixteen of these worms, with cocoons in different stages of 

 development, ranging from a cocoon containing only a trace of 

 albumen and no eggs to one with the full amount of albumen of 

 a mature cocoon, with 28 eggs. These immature cocoons, when 

 removed from the worm, are surrounded by a single slime-tube, 

 resembling one half the double tube found around a copulating 

 pair. This single cocoon lies near the posterior end of the 

 slime-tube (Fig. 3), maintaining the relation that exists between 

 the slime-tube and cocoons in the case of copulating worms, 

 where the two cocoons lie at opposite ends of the double tube. 

 Examination with a lens shows the clitellum of the worm en- 

 cased by the cocoon and part of the slime-tube, the longer 

 part of the tube lying anterior to the clitellum (Fig. i)*. When 

 the worm is not disturbed it will withdraw backward, through 

 the slime-tube and cocoon, finally pulling the head through the 

 smaller end of the cocoon (Figs. 2 and 3). This accords with 



1 We have not been able to find any record other than ours of actual observation 

 of the deposition of cocoons by copulating pairs, or of single worms with cocoons in 

 process of formation. 



