94 RICE. 



that has arisen from this condition of things is whether there 

 may not be a symbiotic relations between the earthworm and 

 these supposed parasites. Are these nematodes instrumental in 

 consuming the chloragogue waste which the worm by other 

 means is unable to eliminate from its body ? 



A detailed study of these waste masses both in preserved (for 

 winter use) and freshly collected material gave these results : 

 The average number of setae (counted in part and estimated) pres- 

 ent in the waste masses of each of the seventeen worms exam- 

 ined was two hundred and forty-eight. The nematodes in 

 the dark-colored waste masses were as a rule few sometimes 

 entirely absent and, when present, in a quiescent state, often 

 enveloped by a sort of cyst. In these dark-colored masses 

 the chloragogue granules far exceeded the nematodes in abun- 

 dance. 



In the light-colored masses, on the other hand, the nematodes 

 were far in excess of the chloragogue granules, and on pressing 

 the cover-slip many of the nematodes, having within their bodies 

 granules apparently identical as to size and color with those of 

 the surrounding waste chloragogue granules, could be excited to 

 move freely and by so doing clearly showed themselves to be 

 unencumbered by any cyst. Their appearance was suggestive 

 of a newly moulted insect. This supposition of a symbiotic rela- 

 tion is then supported to the extent that within the nematodes 

 have been found granules identical as to size and color with 

 chloragogue granules ; and further by the fact that where the 

 nematodes are in excess and in an active condition the chlora- 

 gogue granules as a rule are far less abundant than the nematodes. 

 It should be stated, however, that the nematodes at no time have 

 been seen in the act of consuming the chloragogue granules, 

 though frequently one has patiently sought to observe this. 

 Still the facts seem to justify the suggestion of a possible symbi- 

 otic relation existing between these nematodes and the earth- 

 worms within which they live. 



6> Bouu v/^- ' 1*% 



