MICROSCOPE AND AGRICULTURE 



the fact that many quite unrelated forms of animal 

 life are essential to the well being of a number 

 of parasites. To the farmer the subject is all 

 important. 



Insects of various kinds are all important in agri- 

 culture; most of them are harmful, some few are 

 useful. They have, however, been dealt with in 

 another chapter, so we will dismiss them here. The 

 ticks are closely related, and anyone with access to 

 a farm should be able to obtain some specimens. 

 Whatever species we are able to obtain should be 

 examined under the microscope. Their feet are 

 always interesting, being furnished with powerful 

 claws beautifully adapted to grasping the hairy coats 

 of their hosts. Their mouth parts are quite unlike 

 those of insects, and are always furnished with a 

 number of backwardly directed teeth, which are 

 useful for tearing flesh sufficiently to draw blood on 

 which they feed. 



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