DEPARTMENT OF EXPERIMENTAL EV0I,UTI0N. 89 



is well begun. This attack is being made from six sides — the origination of 

 the character, its chemical basis in the germ-plasm, its ontogenetic develop- 

 ment, its modifiability, its transmissibility, and its relations to the other char- 

 acters and to the external world. 



CHANGES IN STAFF. 



While stability in the resident staff is to be nominally sought for in dealing 

 with problems involving the long-continued breeding of strains of animals 

 and plants, yet a not unimportant part of the work of the Station must be 

 for some years, until the work is more generally introduced into universities, 

 to train young men for positions elsewhere. Dr. Lutz, resident investigator 

 since the beginning of the Station, received and accepted, early in the cal- 

 endar year, a call to the American Museum of Natural History in New York 

 City, where he will take part in making collections and installing exhibits 

 illustrating evolutionary principles. Owing to the proximity of Dr. Lutz in 

 his new position to the Station, his experiments were continued here for 

 several months under his supervision and, by agreement with the direction of 

 the museum, his work on heredity of fruit-flies will be continued there. 



The place vacated by Dr. Lutz has been filled by Dr. R. A. Gortner, re- 

 ferred to in the general part of this report, who will help answer some of the 

 chemical questions that arise in all experiments on the heredity of color-char- 

 acteristics. The vacancy made by the resignation of Mr. R. H. Johnson has 

 been filled by the appointment of Dr. Arthur M. Banta, professor of biology 

 at Marietta College, formerly a student of Prof. Carl H. Eigenmann, under 

 whose stimulus he began and completed an extensive study of the "Fauna of 

 Mayfield's Cave" (Publication No. 67 of the Carnegie Institution of Wash- 

 ington). Dr. Banta will, as stated above, devote himself to a study of the 

 modifying influence of cave conditions upon organisms. Valuable results are 

 to be anticipated from such an experimental study, since, in nature, cave life 

 is associated with striking modifications, such as loss of pigment, loss of 

 sight, and elongation of antennae. Such studies were anticipated at the time 

 the main building was erected but have hitherto not been carried on, awaiting 

 the appearance of a properly equipped investigator. 



DETAILED REPORTS ON SCIENTIFIC WORK. 



WORK ON ANIMALS. 



Poultry. — In this work 55 pens were maintained and 3,005 chicks hatched. 

 One of the vivaria was used for indoor brooding with success. Four fireless 

 brooders were purchased and found to be superior for our purpose over the 

 heated brooders, while their care and expense of maintenance was much less. 

 Two matings were made between white and pearl guinea-fowl. All offspring 

 were of "pearl" color except that they were mottled with large white patches 



