16 REPORT OF THE COMMISSIONER OF AGRICULTURE. 
to be, for this reason, an increasing demand for the services of the 
Bureau of Animal Industry, and the powers of the Bureau should 
be increased and its organization perfected, so that it may accomplish 
the entire work for which it was established. 
In addition to the work for the investigation and control of ani- 
mal diseases, inquiries have been made in connection with many 
special subjects bearing upon the economical production of animal 
products. 
The quarantine of cattle from foreign countries has been main- 
tained during the year by this Department. Owing to the low 
price of cattle in this country the importations have been very small. 
No case of contagious disease has been discovered among imported 
cattle since my last report, and the safety of our quarantine system. 
is shown by the fact that no case of pleuro-pneumonia or other con- 
tagious disease has ever been traced to cattle which have been dis- 
charged from any one of our quarantine stations. 
DIVISION OF ENTOMOLOGY. 
The work of this division during the past year has been signalized 
by the completion of two important investigations; the one upon the 
Cottony Cushion-scale of California, and the other upon the Hop- 
louse. Both of these investigations were mentioned in my last re- 
port. 
From the middle of March until nearly the middle of May the 
Entomologist was in California, concluding the first of these nvesti- 
gations and studying the other insect pests of that State. His ob- 
servations supplemented those made by two field agents of the divis- 
ion, who were stationed in Los Angeles County during the greater 
part of the summer of 1886, and the results are included in the ‘Ane 
nual Report for 1886. Other supplementary facts concerning this 
investigation, bearing for the most part upon the original habitat of 
the species and summarizing an extensive correspondence with natu- 
ralists in Australia, New:Zealand, and South Australia, but also in- 
cluding the resultsof certain experiments with gases against this and 
other scale insects, have been published in Bulletin No. 15 of the 
division. 
As stated in my last report, the Entomologist and one assistant 
visited the hop-fields in September, 1886, and made important obser- 
vations. During the greater part of the present season three assist- 
ants have been stationed in the hop-growing region of New York 
State, one studying the life history of the Hop-louse, and the other 
two experimenting with different remedies, and particularly with 
cheap and effective means for the application of insecticides. Another 
agent was sent to the hop-fields of Wisconsin during August and a 
part of September, where he collected additional information and 
made confirmatory observations. The Entomologist, moreover, has 
