182 JOHN N. LOWE 



eral ganglia and nerve endings. It is highly probable that the 

 action of veratrine on the pigment cells is through the lower 

 centers of the nervous system rather than local. 



Carlson ('06) found that weak solutions of veratrine had a 

 primary stimulating action on the heart ganglion of Limulus. In 

 strong solutions the period of stimulation was followed by a de- 

 pression in two minutes. The ganglion free heart did not re- 

 spond to the poison. Plateau ('78) observed a primary stimu- 

 lation in the heart of Carcinus moenas and Homarus (sp.) which 

 was followed by a depression. Romanes ('77) found that in the 

 medusa Sarsia (sp.) the first effect of veratrine was an increase in 

 the number and potency of the contractions. This period of 

 increased responsiveness was followed by a gradual depression 

 into complete quiescence. 



Summarizing the action of veratrine on the pigment cells, it 

 may be stated, that it first stimulates the contraction of the 

 pigment cells. This period of stimulation is followed later by a 

 paralysis of the mechanism controlling the pigment cells. The 

 pigment cells are expanded during this period of depression. 

 This is in harmony with the observations of other workers on 

 various tissues, where there is observed a primary stimulation 

 followed by a depression. 



10. Quifiine. Quinine in a 0.5 per cent maintained for a long 

 time the pigment cells in an expanded condition. Dilutions were 

 made from 0.25 per cent to 0.0005 per cent of quinine hydrochlo- 

 ride solution, and in all of these dilutions no change occurred in 

 the pigment cells. Solutions of 0.000033 per cent to 0.0000165 

 per cent gave the same result. 



The pigment cells were first contracted in picrotoxin and were 

 then placed in the quinine solutions of 0.025 per cent to 0.005 

 per cent and in every case a rapid expansion of the pigment cells 

 occurred. The rapidity of the expansion was greater in the 

 quinine than it was in the ordinary process of washing out of 

 the picrotoxin. 



Quinine differs from most drugs in that its action is very 

 widespread, and it is often called a general protoplasmic poison. 

 Binz ('68) observed that quinine inhibited the beat of the cilia 



