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RAYMOND PEARL 



and a half old at the beginning of the experiment, and their 

 increase in body weight at this time can not be attributed to 

 growth in the ordinary sense of the term. Examination of rather 

 extensive statistics on body weight changes in poultry indicates 

 that there is some tendency for a bird to increase in weight 



Fig. 1 Diagram showing the changes in body weight of females subject to 

 inhalation treatment. The figures plotted are the means for the specified sorts 

 of birds, except where a statement to the contrary is made. Solid line, un- 

 treated controls; dash line, ethyl alcohol birds; dotted line, methyl alcohol birds 

 (here the plottings after September 1915 are based on a single bird); dash-dot 

 line, ether birds. 



during the autumn and early winter months, quite regardless 

 of her age. I hope later to be able to present exact and compre- 

 hensive data on the normal seasonal fluctuations in the body 

 weight of hens. In the absence, at the present time, of such 

 data, and because of the fact shown by the data given here 

 that this initial rise in body weight in the autumn of 1915 is only 

 slightly less in the controls than in the treated birds, it seems 



