ZOOLOGY. 279 



In investigations with mice, guinea-pigs, and rabbits, the grantee has had 

 the continued assistance of C. C. Little, John Detlefsen, and E. C. Mac- 

 Dowell respectively. Papers embodying the results obtained are nearly 

 ready for publication. 



Several new lines of experiment have been started with guinea-pigs brought 

 from Peru in January 1912. Assisted by a special grant, the writer went to 

 southern Peru in November 191 1, and was there able to secure guinea-pigs 

 of three distinct sorts: (i) a small wild species of Cavia, probably cutleri, 

 about half as large as the domesticated guinea-pig, of a squirrel-gray color ; 

 (2) a supposedly feral guinea-pig resembling the golden agouti domesticated 

 variety; (3) domesticated guinea-pigs as kept for food by the natives of 

 Peru at the present time. 



All these sorts breed readily with the domesticated guinea-pig kept in the 

 United States and Europe. Indeed the ancestors of the last undoubtedly 

 came from South America only a few centuries ago. But the wild ancestral 

 species is still unidentified, and the main object of the Peruvian expedition 

 was if possible to discover this ancestor and see what new varieties, if any, 

 could be derived from it by crossing. What success has been attained 

 remains in part to be determined. 



Hybrids derived from the wild species crossed with the guinea-pig all 

 resemble the wild species, but give promise of attaining larger size. Their 

 fertility is as yet problematical. Hybrids from the supposed feral stock are 

 not uniform in character, but give clear indications that that stock contained 

 admixtures of domesticated blood ; it may even have come wholly from that 

 source. The first cross with both the feral and the native Peruvian stock 

 has produced a variety of guinea-pig hitherto unknown to us. Further 

 results are awaited with interest. 



Five papers have been published by the grantee and two by C. C. Little 

 based on results obtained under these grants. (See Bibliography, pp. 41-43). 



Gudger, E. W., North Carolina State Normal and Industrial College, 

 Greensboro, North Carolina. Grant No. 528, allotted May 12, 1908. 

 Investigation of the breeding-habits and life-history of the gaif-topsail 

 catHsh. (For previous reports see Year Books Nos. 7 and 9.) $300 



The grantee spent the last ten days of May at Beaufort, North Carolina, 

 in the endeavor to get the early stages (the only ones lacking) in the develop- 

 ment of the gaff-topsail catfish, for the drawings of which a grant was made 

 some years ago. 



Naples Zoological Station, Naples, Italy. Grant No. 759, allotted Decem- 

 ber 15, 191 1. Maintenance of two tables for American biologists. (For 

 previous reports see Year Books Nos. 2-10.) $1,000 



During the last term the two Carnegie Institution of Washington study 

 tables at the Zoological Station were occupied by Professor Lambert, of 



