THE PRINCIPLES OF HORTICULTURE. 
503 
their climatic and other neccessities, their peculiarities, their 
modes of growth, and with the functions of their several parts ; 
for this knowledge he must study vegetable'physiology. 
The extremes of temperature to which his plants may be 
exposed and the other atmospheric conditions, such as wetness 
and dryness, and electric phenomena, are all of the greatest 
importance to successful culture of different tribes, and the 
knowledge requisite for the solution of these problems can 
only be obtained from the science of meteorology. 
But there is yet another branch of scientific investigations 
which will require the close study of the horticulturist, so as to 
enable him to protect his plants from the depredations of 
parasitic fungi, from the insects, and from other animal intrud¬ 
ers. This will necessitate the aid of natural history. In this 
branch the study of entomology is especially worthy of atten¬ 
tion, and with the rapid increase and diffusion of noxious 
insects some natural history has become absolutely necessary 
to every one who .devotes himself to the delightful pursuits of 
horticulture. Fortunately for us, noble hearts and willing 
hands, well fitted to the work, have already undertaken to 
popularize this study, and the legislatures of some of our 
states have made provisions for their assistance. 
Tne state of Illinois has Dr. Benjamin D. Walsh as its state 
entomologist; the same position is filled in Missouri by Mr. C. Y. 
Kiley. These gentlemen edit with much ability the American 
EntomologisU a monthly periodical of great value, published 
at St Louis. We have also Townsend Gflover, the eminent 
entomologist of the department of agriculture, Dr. Asa Fitch, 
\\ho holds the position of entomologist to the New York state 
agricultural society, and Dr. Trimble of New Jersey. One of 
the most valuable works we have on that subject is Harris^ 
Injurious Insects, edited by our friend here present, Hon. C. 
L. Flint. 
It must be apparent, therefore, that the principles of horti¬ 
culture constitute a vast scheme, based upon extensive studies 
and stretching over a wide field, so wide indeed, as almost to 
deter one from undertaking to grasp them. Fortunately for us. 
