NO. I SMITHSONIAN EXPLORATIONS, IQIQ 47 



A summary of the results so far obtained from the breeding- 

 experiments has recently been published as a bulletin by the Carnegie 

 Institution. The results are rather startling, and incline one, con- 

 trary to the views previously held by most people, to the belief that 

 Cerions are not easily influenced, if at all, by environmental factors. 

 The cross obtained in the Newfound Harbor colony opens up an 

 entirely new vista in the problem of speciation, and it was this which 

 was res])onsible for the starting of the new set of breeding 

 experiments. 



Incidental to these investigations, which have been conducted since 

 1912, a list of the birds observed on the various keys has been kept 

 and published annually in the Year Book of the Carnegie Institution. 



FIELD WORK ON THE MESA VERDE NATIONAL PARK, 

 COLORADO 



The field-work of Dr. J. Walter Fewkes, Chief of the Bureau of 

 American Ethnology, at the Mesa Verde National Park, in the sum- 

 mer of 1 919, was devoted to the excavation and repair of the pic- 

 turesque cliff dwelling". Square Tower House, known for many years 

 as Peabody House, and two low prehistoric mounds situated among 

 the cedars on top of the plateau. • I'his work was a continuation of 

 that of previous years and was carried on in cooperation with the 

 National Park Service of the Department of the Interior. As Square 

 Tower House has several unique structural features, the summer's 

 work has added to the educational attractions of the Park. At least 

 two new types of hitherto unknown small-house ruins were dis- 

 covered, and it is believed that a new page has been added to the 

 history of the Mesa Verde cliff" people. Dr. Fewkes was assisted in 

 his field-work by Air. Ralph Linton, a temporary assistant, who con- 

 tributed much to the success of the work. 



The main object was to gather data that may aid one to better com- 

 ])rehend the Indian civilization that arose, flourished on the Mesa 

 Verde, and disappeared from the plateau over four centuries ago. 



Square Tower House is situated in a shallow cave at the head of 

 a s]nir of Navaho Canyon opposite Echo Cliff', about 2 miles south 

 of Spruce Tree Camp. It has long been considered by tourists one of 

 the most attractive cliff' dwellings of the park, but its inaccessibility 

 lias deterred all but the most venturesome from descending to it from 

 the rim of the canyon. Part of the old Indian trail ( fig. 47) was indi- 

 cated by shallow foot holes cut in the almost perpendicular cliff's, and 

 previous to the past summer this was the only means of access. 



