20 J. WILLIAM BUCHANAN 



used in this work did the pieces increase in weight. Whether 

 this increase in chloretone solutions is due to the imbibition of 

 water by the tissues or to imbibition of water by the adherent 

 mucus which they extrude is not possible to say at present. 

 The data on the increases in weight are given in full in table IB. 

 Consideration of the data on oxygen consumption will be con- 

 fined to those experiments in which the rate is calculated on the 

 weight of the pieces before the test, since that is the more nearly 

 correct weight of living material. The weighing before the 

 tests of oxygen consumption might possibly increase the stimu- 

 lation of the pieces, which should be evident in a higher rate of 

 the control and to some extent in the chloretone series as well. 

 But no increase of rate due to weighing is evident in the controls 

 if we compare them with the controls in which the weighing was 

 done after the test. And without exception the pieces in the 

 chloretone had a much lower rate of oxygen consumption than 

 that of their controls. In fact, there are indications that not 

 only is stimulation largely or entirely prevented, but that there 

 is also some degree of depression below the rate of oxygen con- 

 sumption of whole animals. It must be pointed out that any 

 depression below the rate of whole animals, since it is not merely 

 the prevention of stimulation, but a general protoplasmic effect, 

 must strongly affect the X cells. This depression, therefore, 

 throws some light on the decreases in head frequency, so general 

 in A pieces, and occasional in B pieces, and in one case, series 2, 

 occurring in C pieces. 



Chloroform 



Head frequency. In general, the results obtained by treating 

 pieces with various concentrations of chloroform for short periods 

 immediately after section were similar to those obtained with 

 chloretone. Table 2A gives in detail the least and greatest 

 changes in head frequency obtained. Seven experiments were 

 carried out in which the number of deaths, aways high in chloro- 

 form, did not obscure the basis for comparison with the control. 

 The increases in head frequency in both B and C pieces were 

 noticeably greater in the chloroform experiments than in those 



