282 REPORTS ON INVESTIGATIONS AND PROJECTS. 



anions, e. g., the toxicity of SrCl 2 — which is quickly destructive in 

 pure solutions — is greatly diminished by the addition of small quan- 

 tities of Na salts with the anions OH, As0 4 , CN, Br0 3 . The action of 

 the cation preponderates in the salt, and hence addition of anions 

 has an antitoxic action. 



(7) The action of the cations is, in general, to cause coagulation 

 of the protoplasm of the ciliated cell, while the anions cause absorp- 

 tion of water, indicating the reverse effect. The effect is, in general, 

 more marked, the lower the decomposition-voltage and the greater 

 the valence of the anion. Ionic velocity also appears to play a part 

 in this action. 



III. Contractility of Swimming Platk of Ctfnophore. 



The research was conducted at the Zoological Station, Naples. 

 The swimming plate of Eucharis lobata was chiefly used. 



(1) An extensive study of the action of salts was made. In general 

 the results of this correspond to those summarized above for the 

 ciliated cell of Mytilus, with various typical differences to be described 

 in the full report. 



(2) A connection between a coagulation of the colloids of the 

 swimming plate and the contractility of the plate was found to exist. 

 Contractility apparently depends on a change in the aggregation- 

 state of the colloids similar to that which occurs in coagulation, i. e., 

 a coalescence of adjacent colloid particles. In the living and active 

 plate the change is apparently reversible in its nature. 



(3) In the propagation of the contraction-impulse from one plate 

 to the next, continuity of the ciliated cells is not necessary. Appar- 

 ently the impulse can be transmitted across the general surface of 

 the jelly composing the body of the animal. 



McClungf, C. E., Kansas University, Lawrence, Kansas. Grant 

 No. j 6. Comparative study of the spermatogenesis of insects. 

 (For previous reports see Year Book No. 2, p. xliii, and Year 

 Book No. 3, p. 139.) $500. 



Abstract of Report. — The investigations have been continued with 

 the purpose of discovering whether there is any constancy in the 

 chromosome complex of the germ cells and, if there is, whether there 

 is any discoverable connection between particular chromosomes and 

 definite groups of body characters. By the study of a considerable 

 number of species belonging to the family Acridiidse it has been 

 found that there is a constant number of chromosomes for the 

 family, and that different genera have characteristic sizes and group- 



