NEw YorK AGRICULTURAL EXPERIMENT STATION. 61 
GENERAL PLAN OF THE INVESTIGATION. 
Our studies for the past two years have been conducted with 
milch cows and in connection with observations that are to fol- 
low have been arranged in accordance with the following general 
plan. 
1. Feeding to the same animal during short or long periods of 
time rations differing greatly in the amount of phosphorus which 
they supply, this variation in phosphorus content to be brought 
about, as far as possible, by selection of the components of the 
ration, but the differences in quantity of ingested phosphorus 
to be intensified both by special treatment of the ration and by 
adding to it particular phosphorus-bearing bodies, the effect of 
which it is desired to study. 
2. Modification of the phosphorus content of the ration by varia- 
tions as far as possible in the amount present of a particular phos- 
phorus-bearing body. 
3. The changes from a high, to a low, phosphorus ration to be 
both abrupt and gradual. 
4. The maintenance of the rations on the same nutritive plane, 
excepting in the variations of the phosphorus content. 
5. Lhe feeding of weighed and carefully sampled rations and 
the collection and weighing of the excreta and product, to be 
accompanied by such chemical determinations as are essential to 
the solution of the problem in hand. 
It was expected that this plan of work would furnish data on 
the following points. 
1. The amounts and kinds of phosphorus-bearing bodies in cer- 
tain cattle foods. (Already published.) 
2. The transformations and distribution of phosphorus-bearing 
bodies brought about by the metabolic changes in the animal. 
3. The influence of the supply of phosphorus compounds both 
in kind and in quantity, upon the physiological status of the animal 
and upon the composition and yield of product, whether milk or 
otherwise. 
