CONTROL OF HEAD FORMATION IN PLANARIA 29 



With large animals ten weeks of starvation in the presence of 

 the alcohol are required to bring about such a great increase in 

 rate. During this exposure to alcohol the animals do not lose 

 weight any more rapidly than their controls in water and, al- 

 though their rate of oxygen utilization is many times that of 

 the control, they move about less than the control animals. 

 These data indicate that the alcohol is oxidized more and more 

 rapidly as the progress of starvation increases the general metab- 

 olism of the animals and that this high rate of oxidative reac- 

 tions apparently due to oxidation of the alcohol is accomplished 

 without appreciable loss of protoplasm. The observations 

 also indicate that the high rate of the oxidative reactions in the 

 animals subjected to alcohol solutions does not result from ner- 

 vous stimulation. 



That the pieces of Planaria are very considerably anesthe- 

 tized in solutions of ethyl alcohol up to mol. 1/10 is certain. 

 It is also certain that nerve or other conducting paths narcotized 

 by alcohol do not transmit stimuli. Therefore, any tissue activ- 

 ity concerned in oxidizing the alcohol in solutions strong enough 

 to produce anesthesia is not induced by the stimulation of sec- 

 tion. In fact, Winterstein ('14) has shown that alcohol nar- 

 cosis may be produced in nerve tissue itself with an accompany- 

 ing increase in oxygen consumption. Furthermore, because 

 of the narcosis of the conducting paths by the alcohol, the tis- 

 sue activity of the Y region cannot exert any influence on the 

 X region and vice versa. If this is true, the relations of the X 

 and Y regions in pieces in alcohol are thus essentially the same 

 as in the other anesthetics employed. 



A strong probability has therefore been established that the 

 relatively high rate of oxygen consurnption of pieces subjected 

 to solutions of ethyl alcohol results from the oxidation of the 

 alcohol, and not from the stimulation of section, and that the 

 measurement of the rate of oxygen consumption in such pieces 

 is complicated by the oxidation of the alcohol in the tissues of 

 the pieces. A further complication is introduced by the injury 

 to the tissues in the stronger solutions. There are also sound 

 reasons for believing that the tissue activity induced in the Y 



