176 REPORT OF OFFICE OF EXPERIMENT STATIONS. 



four digestion :uul inotabolisiii periods, seems to show quite clearly 

 that the amount of potential energy stored up in a jjound of gain 

 of live weight was materially greater in the ease of the pure-bred 

 animal. It is concluded that a pound of increase in the pure-bred 

 animal, therefore, had a higher value as human food than an equal 

 increase in the scrub. 



The institute is conducting investigations on the frontier of animal 

 nutrition. It is equipped as no other station in this country is for 

 this special study; and its work while very technical has already 

 proved highly practical. It is fortunate for our knowledge of the 

 underlying principles of animal nutrition that the State and the 

 (leneral (Jovernment have united in promoting advanced investiga- 

 tion in this field. 



PORTO RICO. 



Porto Rico Agricultural Experiment Station, Mayaguez. 



Under the supervision of A. C. True, Director, Office of Experiment Stations, 

 United States Departmeut of Agriculture. 



D. W. May, M. Agr., Special Agent in Charge. 



The office and laboratory building provided for by the insular 

 government has been completed, arid the station for the first time is 

 now" adequately housed. Some changes were made during the fiscal 

 year in the personnel of the station. M. J. lorns, horticulturist of 

 the station for three years, died May 17, and was succeeded by C. F. 

 Kinman, formerl}^ assistant horticulturist at the Cuban Experiment 

 Station, with T. B. McClelland as assistant. G. L. Fawcett, formerly 

 connected with the subtropical laboratory of the Bureau of Plant 

 Industry of this Department, w^as transferred to the Porto Rico 

 Station as plant pathologist, and William Hess, of the same labora- 

 tor}', was transferred as expert gardener. Dr. William C. Taylor, 

 of Harvard University, was appointed assistant chemist, and Dr. 

 Oscar Loew returned to the station for a few months to carry on 

 some investigations relating to soil problems. 



The chemical work of the station has been largely a study of soils, 

 tropical soils presenting problems totally distinct from those in the 

 temperate regions. The investigations now in progress principally 

 relate to nitrogen, the activit}^ of enzyms, and drainage waters. The 

 practical side of these investigations looks toward tke renovation of 

 those soils that are worn out from continuous cropping. 



The work of the horticultural department is largely devoted to 

 plant breeding and acclimatization, and besides the very extensive 

 work at the station cooperative experiments are in progress with 

 representative planters in different sections of the island. 



The work of the division of plant physiology and pathology has 

 largely been confined to diseases of citrus fruits and pineapples, and, 



