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HALE HOURS WITH INSECTS. [Packard. 
of many plants, are but examples of the multitudes of ways 
in which this dependence of plant and animal exhibits itself. 
The theory of the science of agriculture, now so far per¬ 
fected, seems adequate to the end. Every year adds to the 
perfection of the seed to be sown, as agriculturists are 
paying more attention than formerly to a careful selection of 
the best fruits and seed. The chemistry of plants, of nutri¬ 
tion and absorption, all the daily routine of plant life, has 
been mapped out by Liebig and his followers. The care of 
flocks and herds and their improvement have made our far¬ 
mers actually better acquainted with the principles of in-and- 
in breeding, or the secrets of “natural selection” than many 
naturalists. Indeed, the facts already brought out by prac¬ 
tical writers on this subject are important contributions 
towards a theory of the method and permanent effects of 
specific variation, a point now so interesting to naturalists. 
Agricultural mechanics, in its constant endeavor to lighten 
toil and economize time, thus leading to the increased intel¬ 
ligence of the laborer, is daily enlarging its borders. New 
inventions of reaping and ploughing machines and labor 
saving machinery of every description are constantly devised, 
so that we may consider the theory of agricultural science 
far advanced toward perfection. 
Now come in some disturbing agencies, such as tempests, 
prolonged rains, severe droughts, rust, mildew and injurious 
insects. Their appearance cannot be prognosticated, their 
direful effects once experienced cannot be immediately reme¬ 
died, nor the remedies when discovered be always seasonably 
applied. The last mentioned cause of disturbance will now 
engage our attention. 
Nearly every one can recall the sudden and simultaneous 
uprising of the army worm in New England during the 
summer of 1861. Its ravages have been known and dreaded 
yearly in the western states, where at intervals it has done 
wide and extensive damage. Though in a local history a 
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