CHICKS HATCHED FROM ALCOHOLIZED EGGS 105 



chicks than that of the normal chicks. The different reactions 

 will be taken up in detail in the following pages. 



We are happy to have this opportunity to express our lasting 

 gratitude to President B. V. B. Dixon for hearty co-operation 

 in the experiment and to Dr. Irving Hardesty and Dr. Gustav 

 Mann, of the Medical College of Tulane University, to whose 

 suggestions for technique we owe much. Our greatest debt is 

 to Miss Ellinor H. Behre, of the Department of Biology, whose 

 biological resourcefulness and unmeasured helpfulness in the 

 carrying on of the work made it possible. To Professor J. A. 

 Lyon, of the Department of Physics, we are indebted for the 

 apparatus used in the experiments with reactions to light. To 

 Professors Angell and Carr of Chicago University we are also 

 indebted for valuable suggestions. 



EXPERIMENTS WITH INHERITED REACTIONS 



Reactions to Light 



The apparatus used to test the first reactions to light of the 

 first set of chicks consisted of a hooded light placed behind a 

 cardboard screen in such a way that a single horizontal strip 

 of light 5 mm. in width was visible between the screen and the 

 table, affording a single, highly localized stimulus. The experi- 

 mental table stood in a dark room used for photographic pur- 

 poses. No light was permitted to enter the incubator from the 

 nineteenth to the twenty-fourth day of the hatch. 



On the twenty-fourth day the incubator was taken to the 

 dark room. Fourteen chicks, seven normal and seven alcohol, 

 (the extent of the hatch) were removed from the incubator 

 one at a time, numbered and marked with cloth markers and 

 placed one at a time on the experimental table eighteen inches 

 from the stimulus. Of the seven normal chicks only one re- 

 acted definitely. This chick walked towards the light, stopped, 

 went on towards the light, stopped, then went straight to the 

 light streak and tried to nestle in a corner of the screen. Four 

 of the seven normal chicks walked away from the screen. Of 

 the seven alcohol chicks, five went to sleep after making a few 

 random movements, one stood still screaming and one ran 

 about the table, finally running off and up the experimenter's 

 arm. Light was thrown on the heads of the first two chicks 

 which were tested but elicited no response. . 



After this test this apparatus was discarded because so much 



