22 Director's Eeport of the 



time. Nine species of the natural enemies of these insects have 

 also been studied and illustrations made showing the different 

 stages in their development. 



Experiments in spraying currant bushes and plum trees showed 

 that these lice may be destroyed if a whale oil soap solution, one 

 pound to seven gallons of water, is properly used. 



The cotton-wood leaf beetle. — The investigations and experiments 

 with this insect were finished during the past season. 



The field used the previous year was sprayed with green 

 arsenite, former experiments having shown that this insecticide 

 would probably prove the most effectual of any tried. Three 

 applications were made, with the result that the plat was kept 

 almost entirely free from the insects. 



In comparing the cost of spraying and running the '' bug 

 machines," or '' drags," it was found that the spraying could be 

 done at about two-thirds the expense of the other method. It 

 was also found, however, that under ordinary circumstances the 

 best results would be obtained by using the '' machine " for a 

 few days soon after the last application of the poison. 



Department of Animal Industry. 



Feeding experiments with chicles and capons. — From an extended 

 test of the relative efficiency of whole and ground grains in feed- 

 ing chicks and capons it was learned that more food was eaten 

 and a more rapid and profitable gain was made when the ground 

 grain was fed. 



Source of milk fat. — An extended and somewhat elaborate 

 investigation concerning the source of milk fat was begun early 

 in the year and the results so far as reached were published in 

 Bulletin 132. 



The data show clearly that food fats are not essential to the 

 formation of milk fat, and that the milk fat was not derived 

 wholly from the metabolism of protein; but that probably its 

 origin was partially in the carbohydrates of the food, as has been 

 demonstrated to be the case with bodv fat. 



