276 REPORTS ON INVESTIGATIONS AND PROJECTS. 



Castle, W. E., and Mark, E. L., Harvard University, Cambridge, 

 Massachusetts. Grant No. 249. Experimental studies in he- 

 redity. (For first report see Year Book No. 3, p. 136.) $600.* 



Drs. Castle and Mark are associates of the Station for Experi- 

 mental Evolution at Cold Spring Harbor, and their work has been 

 done in cooperation with that of the station. 



Abstracts of Reports. — Dr. Castle reports that most of the experi- 

 ments in progress a year ago have been continued up to the present 

 time. A large amount of valuable material has been accumulated 

 and in part studied. About 2,400 guinea-pigs and 450 rabbits have 

 been reared from pedigreed stock. Experience acquired in previous 

 years has enabled the investigators to avoid certain difficulties in 

 winter breeding, so that the animals have been kept quite free from 

 disease and have bred throughout the year without interruption. 



The experiments and observations relate chiefly to inheritance of 

 coat and skin pigments, hair length, hair arrangement, polydactylism, 

 mammae, individual size, and sex. Some selection experiments for 

 the fixation of particular color patterns have yielded interesting 

 results and promise much for the future. Some light has been 

 thrown upon the phenomena of latent inheritance and reversion. A 

 fine example of blending inheritance has been found in the heredity 

 of ear- character in rabbits. 



Two brief papers and one of a more extended nature have been 

 published during the year, based upon the results obtained from 

 these experiments. Another detailed paper is in preparation. 



Dr. Mark reports that through the generous cooperation of Dr. 

 Davenport the material necessary for the studies has been bred and 

 will soon be ready for histological study. The grant was to pay for 

 the cost of making the necessary histological preparation. 



Crampton, Henry E., Columbia University, New York, N. Y. Grant 

 No. 137. Determination of the laws of variation and inheritance 

 of certain Lcpidoptera. ( For previous reports see Year Book No. 2 , 

 p. xli, and Year Book No. 3, p. 136.) $500. 



Report. — During the past year efforts have been directed toward 

 the acquisition of an abundance of pedigreed material of thesaturnid 

 moth Philosamia cynthia. More than 800 members of the first and 

 second pedigreed generations obtained in 1904 emerged during May 

 and June, 1905. These were mated when possible, and statistics 

 relating to more than 300 families were obtained. As upward of 

 31,000 eggs were deposited by the female moths, it was manifestly 



*Of this amount $500 was allotted to Dr. Castle and $100 to Dr. Mark. 



