ENTOZOA. 453 



aquaticus (fig. 1009), or Hairworm. It lays eggs, which are supposed 

 to be devoured by insects and developed in their bodies. 



It is impossible to describe all the entozoa which live in the nume- 

 rous creatures inhabiting my garden, and still more so to describe the 

 different states in which these creatures live, with their wanderings. 



MITES. 



We have numerous species of Mites in my garden, of which I have 

 many specimens in my microscopic cabinets. The Acarus domesticus 

 lives upon cheese, and the Tyroglyphus farince 

 (fig. 1010) upon flour. One species is parasitic 

 on man in a diseased state, namely the Sar- 

 coptcs Scabici, both of which I have seen in the 

 hospitals in London and in Paris. There are 

 many species which live upon animals ; such as 

 the Mouse Mite (Myobia musculinus) on the 

 mouse; others upon birds, as the Sparrow 



FIG. 1010. Tyroglyphus farinae, 



Mite. Some mites live upon other insects : 



we constantly see one species of mite, the Gamasus coleoptratorum, 

 upon the great dor beetle: and in our streams there are many kinds 

 of mites. One species is terribly destructive to our cabinet insects, 

 namely the Tyroglyphus destructor. 



PLANT MITES, OR RED SPIDERS. 



Plant mites are a most terrible pest to the horticulturist. Although 

 so small, they come in vast armies and spin a thread on the under 

 surface of the leaves of plants, where they live and suck their juices. 

 After a time the leaves perish, the plant is injured, and ultimately dies. 

 The conditions generally favourable to the increase of these pests, are 

 dryness of the atmosphere with scorching suns. In our plant-houses 

 we generally keep down the mites by ensuring a humid atmosphere, but 

 in July it is difficult with us to grow melons in our district, on account 

 of the number of these creatures which take possession of our frames. 



