452 THE MICROSCOPE. 



microscopic pests must be evident, from the fact that the 

 type of the family to which the whole of them belong, is 

 the noisome parasite of the human subject ; another, as 

 yet undetermined form, but of the same tribe, is thought 

 to be connected with one of the most fatal ailments 

 of the frame dysentery; that two distinct Sarcoptes affect 

 the horse and sheep ; and even the common sparrow, our 

 little pet canary-bird, and the useful bee, have not escaped 

 the ravages of the family. The Acarm autumnalis, so 

 very common in the autumn upon grass and other herb- 

 age, insinuates itself under the skin at the roots of the 

 hairs, producing a painful irritation; this is known in 

 some parts of the country as the harvest-bug. 



" When, therefore, we reflect on the evils which these 

 produce, and on the diminutive size of the creature which 

 in its effects is so destructive to other tribes ; and bear in 

 mind that this mere speck, this particle of dust, is 

 organised for all its purposes as completely as the most 

 perfect of any of the whole sub-kingdom to which it 

 belongs, even to the flexor, the extensor, and the rotator 

 muscles of its truly atomic limbs ; while the entire body 

 of the creature, when first produced, measures scarcely 

 more than the 16,000th of an inch in length ; and then 

 call to mind that the mere foot of the Dinornis, or of the 

 Palapteryx, the ancient colossal bird of the antipodes, 

 measures, as shown by Professor Owen, more than 750 

 times the whole size of this little body, who can but feel 

 astonished at the range of creation ? Who can but feel 

 that the study of natural history, not as the amusement 

 of an hour, but as a sober contemplation, must tend to 

 exalt as well as to extend the human intellect, and that 

 the most microscopic atom of organised life, considered as 

 part of the world, is as deserving of our fullest attention 

 as the most gigantic ? " l 



The Louse (fig. 220, No. 1). Whenever wretchedness, 

 disease, and hunger seize upon mankind, this horrid 

 parasite seldom fails to appear in the train of such 

 calamities, and to increase in proportion as neglect of 

 personal cleanliness engenders loathsome disease. When 



(1) George Newport.Esq., F.R.S,, "On anew genus of the family Chalcididce, 

 found in the nest of the bee." Linnean Society's Transactions, 1853. 



