222 



J. S. HUXLEY. 



terminal rounded portion markedly disintegrated, and the current 

 produced by the lateral cilia had .ceased. 



In Nos. i and 2, one piece in each was similar, but the others 

 had scarcely begun to disintegrate. No. 3 was intermediate. In 

 Xos. i, 2, and 3 the current produced by the laterals was still 

 evident. 



After 24 hours, No. 4 was very markedly disintegrated, and no 

 ciliary movement was visible. In Nos. i and 2, 4 of the 8 pieces 

 showed ciliary movement, and the disintegration was not so marked 

 as in No. 4. No. 3 was intermediate. The conclusion was appar- 

 ently to be drawn that it is the total amount and not the concentra- 

 tion of the Hg + ions present that is operative; but the concentration 

 used was apparently too high. The experiment was therefore re- 

 peated in a modified form: (5) Five finger bowls were prepared 

 with 5 pieces of gill in each. In them were placed respectively 

 5, 20, 50, 100 and 300 c.c. of a n/i, 500,000 HgCL, solution. 



The following table gives the results observed (-(- = strong 

 ciliary action ; e - - moderate ; = = faint ; o = very faint ; 

 = no ciliary action. ((D)) =3 slight disintegration; (D) = 

 medium; D== marked disintegration. 



TABLE II. 



It will be seen that the effect of the HgCU was a function of 

 the total amount used, all the solutions being of the same strength. 

 The death of the proximal portions of the filaments was very 

 striking in the large bulks of solution. 



i Numbers 3 and 4 were not observed at 70 hours, owing to an oversight. 



