DEPARTMENT OF EXPERIMENTAL EVOLUTION. 125 



her a set of these rats in order to preserve the hnes and to obtain later gener- 

 ations. Various adverse conditions defeated this purpose. She reports upon 

 this attempt as follows: 



" 'An attempt was made during the year of 1918-19 to continue the alco- 

 hohzation of Dr. MacDowell's strain of rats into the third generation for 

 further study to be taken up after the war. The first and second alcoholized 

 generations and their offspring having been studied, the aim was to breed for 

 the third alcoholized generation, from which it was hoped to obtain material 

 for further study of the effect of alcohol on the germ-plasm. With this point 

 in view, a few of his rats were transferred August 18, 1918, to the Institute of 

 Anatomy of the University of Minnesota, where I could see to the experimental 

 part of the work during my stay at that institution. This was made possible 

 through the kindness of Dr. C. M. Jackson, who granted all the housing 

 necessary for the animals and the help of the service-boy. 



" 'Three pairs of alcoholized rats of alcohoUzed parents with their respective 

 controls made the material for obtaining the third generation of this strain. 

 In addition to these a group of 5 test rats (non-alcoholic, but of alcohoUzed 

 parents and alcoholized grandparents) was transferred for the study of fertil- 

 ity. This group had been trained in the circular maze and in the multiple 

 choice or trial-and-error problem. Still another group was added. This 

 consisted of a htter of 5 rats (Fi) which were the result of a cross of white with 

 pink-tipped hair. This character I had noticed in Dr. MacDowell's stock 

 during the year 1918. In seeing the material while on a visit to this Station, 

 Dr. Castle suggested that this trait could be a possible allelomorph of albinism, 

 or that such coloration of albino hair might be a skin secretion and not a true 

 hair-pigment. The aim was to carry the cross into F2 to see if the trait of 

 pink-tipped hairs is inherited and in what manner. 



"'At Minnesota the rats did not fare well. After a strenuous journey 

 they had to readjust themselves to new environmental conditions, such as 

 temperature, cage conveniences, and a change of diet. They had been ac- 

 customed to receive a daily ration of wheat bread soaked in fresh milk and all 

 the dog bread they wanted. This dog bread was a special make, which, 

 according to the chemist, Mr, Halloway, is a well-balanced food for animals 

 or men, and hence had the necessary vitamines. The change was from this 

 diet to bran bread soaked in fresh milk and dry corn. After a month of this 

 diet the rats had lost from 10 to 22 per cent in gross body-weight. The 

 mortahty was high, and in order to save the stock their former diet was 

 restored in November. From the three pairs of alcoholized rats offspring 

 were obtained and four matings made. These were alcoholized from the time 

 of weaning (28 days), but no offspring were had from them, though they lived 

 to maturity. During the winter an epidemic of a digestive disorder took a 

 few of the rats away. Of the second and third group of rats, breeding was 

 continued and the results of fertihty and color inheritance recorded. 



" 'The hope of saving the alcoholized strain was not realized, principallj'" on 

 account of the lack of reproduction, the mortality, and the environmental 

 conditions.' 



"This summer all the time of Miss Vicari has been devoted to the rat data. 

 To obtain a preliminary survey of the results bearing most critically upon the 

 question of the inheritance of the changes caused by the administration of 

 alcohol, the work has been focused upon the rats whose grandparents only 

 had been given the alcohol treatment, and upon the controls, rats whose 

 grandparents were normal, the brothers and sisters of the alcoholized grand- 

 parents of the rats under consideration. A year ago (Year Book, 1918, pp. 

 109-114) Miss Vicari gave the preHminary summaries for a group of 5 such 



