June, 1919] ANNUAL REPORTS. 15 



In 1913 the project was again revised under the direction of J. M. Jones in 

 co-operation with C. B. Davenport. 



Under the revised project a new schedule was added in a cross between South- 

 down and Rambouillet to be carried out along Mendelian Unes of hybridization. 



The object as stated was "to determine the principles involved in fixing 

 certain characters in sheep, studying the closeness with which the characters 

 of the hybrids follow Mendel's Law, and their apphcation to breeding problems." 



Under this revised project the work is still being carried on although minor 

 changes have been made, such as adding new methods and a general broadening 

 in the scope of the data collected. 



Progress. 



The present head of the Department has been in charge of this work since 

 February, 1915. Up to that time a mass of material had already been col- 

 lected but, aside from the pubhcation of the bulletin on the "Inheritance of 

 Horns in Sheep," no information of technical importance had been worked out 

 or published. 



Since February, 1915, several lines of investigation have been worked up 

 and pubhshed under the following titles: 



1. Mendelism of Short Ears in Sheep. 



2. Ewes' Milk; Its Fat Content and Relation to Growth of Lambs. 



3. Nature and Rate of Growth in Lambs During the First Year. 



4. Family Performance as a Basis for Selection in Sheep. 



5. A Chest Contour CaUper and Its Adaptabihty for Measiu-ing Sheep. 



An artiole on conformation of Rambouillet and Southdown sheep and on their 

 Fi and F2 Hybrids is under preparation and will be published within a year, and 

 a number of articles of a technical nature, on the inheritance of conformation, 

 especially as regards chest contour or shape, on wool covering, inheritance of 

 color, skin folds, ear postiu-e, and wool characters are outHned and will be put 

 into print as soon as the material can be worked up. 



The Hampshire-Rambouillet cross has reached the F4 generation and is now 

 being gradually eliminated, partly by dissemination of the better stock among 

 farmers, and the Southdown-Rambouillet cross is now at the beginning of the 

 F2 stage where sufficient numbers are becoming available for studying the 

 results of segregation. 



After this has reached the stage where a more rigid selection of stock can be 

 made, only those individuals that possess the desked combination of traits are 

 to be retained as a flock foundation of a new type and a greater amount of 

 attention will be given to a study of the inheritance of the causes of twin 

 inheritance and the milk yield of ewes which are fimdamentally the important 

 factors that determine profit in a lamb crop. 



NUTRITION EXPERIMENTS. 



During the fall of 1918 the work of the Department was broadened by the 

 addition of research work in animal nutrition, especially relating to the main- 

 tenance of animals during the winter period. 



On the suggestion of Dr. F. G. Benedict of the Nutrition Laboratory of the 



