REPORT OF THE SECRETARY. 141 



ical narrow ration, and this conclusion is confirmed by extensive 

 investigations at the Minnesota station, where the health and pro- 

 duction of cows from calfhood has been studied and checked by lab- 

 oratory examinations. 



The extensive dairy investigations carried on by the Missouri sta- 

 tion in cooperation with the Department have thrown much light on 

 the efiiciency of food in milk and butter production. 



The role of bacteria in relation to the keeping quality of milk and 

 butter has been investigated with great thoroughness at the Michi- 

 gan station, and many facts have been established which have an 

 important bearing upon practical dairy methods. Most interesting 

 facts have been brought out in these investigations \v4th reference to 

 the varying behavior of the organisms found in milk and butter when 

 working alone or in association with one another and in their resistant 

 power imder different conditions. It has been shown that a large 

 proportion of the harmful organisms succumb to ordinary sanitary 

 dair\^ methods; but one group has been isolated and studied which 

 not onlv survives but is active in a 12 per cent salt solution at — 6° C. 



The Towa station, among other things of immediate practical value, 

 has shown the expensiveness of condimental foods as compared with 

 standard feeds of equal nutritive value and the danger of the forma- 

 tion of urinarv^ calculi in long-continued feeding of roots to breeding 

 sheep. This station has also demonstrated a number of efficient sub- 

 stitutes for oats in rations for horses. 



In pollination experiments with apples at the Oregon station only 

 15 out of 87 varieties were self-fertile, and the self-fertile varieties 

 were improved in size by cross-pollination. A number of suitable 

 pollenizers for commercial varieties of apples have been determined. 

 The possible variation of the same kind of fruit growni in different 

 climates is indicated by some work recently reported by the Massa- 

 chusetts station, where Ben Davis apples from various sections of 

 the United States and Canada were collected and studied. Generally 

 speaking, this variety gradually becomes more elongated in form the 

 farther north it is gro^vn. Upon correlating the variations in fruit 

 characteristics with the variations in meteorological data, it appears 

 that the poor quality of the northern-growTi Ben Davis is due to an 

 insufficient amount of heat to fully develop the fruit. Apple orchard- 

 ing in the New England States has recently been given marked 

 attention by the stations, with a view of extending the industry 

 through improved methods of culture, harvesting, packing, grading, 

 and cooperative marketing, so successfully employed in the apple 

 district of the Northwest. 



Considerable work has been done at both the South and North 

 Carolina stations leading to a better knowledge of the Scuppernong 

 and other Rotundifolia grapes which are found to be especially 



