550 R. A. SPAETH 



3. Degeneration always occurs in the phase opposite to that 

 of the initial one. 



c. Comparative effects of the alkaline chlorides. After the lyo- 

 tropic series had appeared so clearly in the case of the anions of 

 the neutral potassium and sodium salts, further experiments 

 were carried out to determine the nature and sequence of the 

 physiological effects of the alkaline metals upon the chromato- 

 phores. For this purpose a comparative study was made of 

 the chlorides of these metals. In the earlier experiments sodium, 

 lithium, (ammonium), and potassium were used. Subsequently, 

 through the courtesy of Prof. C. P. Baxter, the chlorides of caes- 

 ium and rubidium were also secured and compared with the other 

 four salts. Experiments with the first four salts showed the fol- 

 lowing relationships. 



August 27, 1912 



4:33 P.M. Scales from a 7.5 cm. female were placed in 8 cc. of 0.1 

 M NaCl, LiCl, NH4CI, and KCl, respectively. These 

 contracted in the order 



K>NH4>Li>Na 



(T. = 25.5°C.) There were six scales in each set. 



4.54 P.M. The xanthophores in the LiCl were contracted but expanded 



in the other three solutions. 

 5.40 P.M. The xanthophores were contracted in all but the KCl so- 

 lution. 



5.55 P.M. A relaxation appeared in all the melanophores in NH4CI. 



.8.30 P.M. The melanophores in KCl showed the beginning of degen- 

 eration. In NH4CI the melanophores were partially ex- 

 panded but without signs of degeneration. The NaCl 

 and LiCl solution both showed contracted melanophores 

 and no sign of degeneration. 



12.15 A.M. (August 28, 1912) Marked degeneration appeared in the 

 NH4CI solution. 

 7.00 A.M. The scales in LiCl showed the melanophores half expanded. 

 5.15 P.M. The melanophores in NaCl responded to atropine sulphate 

 by expansion (more than twenty-four hours after begin- 

 ning the experiment). 



This type of experiment was repeated with entirely uniform 

 results. Although the KCl and NII4CI are clearly distinguish- 



