206 



C. M. CHILD AND L. H. HYMAN. 



68, 69, Janus green 1/10,000). In Fig. 68 disintegrated entoderm 

 is issuing from the mouth. Figs. 70 and 71 show another case, 

 an animal with advanced bud in Janus green 1/200,000 approxi- 

 mately. In this low concentration the contraction is less extreme 

 but the course of disintegration is the same as in the higher con- 

 centration. In these very low concentrations where the body 

 contractions are less extreme, disintegration often appears at 

 the anterior end of the stalk at about the same time as in the 

 body (Fig. 72). In methylene blue the picture as regards both 



jag* 



68 



74 



behavior and disintegration is essentially the same, but the degree 

 of irritation with a given concentration is less than in Janus green. 

 In these dyes, as in alcohol and ether, the relatively early paral- 

 ysis of tentacles and hypostome, the great activity of the body 

 and the less extreme activity of the stalk alter the regional sus- 

 ceptibility relations so that disintegration and death begin rela- 

 tively early in the body and often in the stalk, as compared with 

 tentacles and hypostome. 



As regards Hydra viridissima the results in ether 2-3 per cent. 



