A CHAPTER ON INSECTS 127 



(Fig. 25), on account of his talents as an observer, his 

 gifts as a writer and his direct appeal to a non- 

 technical audience is probably more widely known 

 than any other entomologist. Those who wish to 

 taste the flavors of this charming writer on natural 

 history are recommended to look into his volume on 

 The Hunter-Wasps. 



Other entomologists, more important from the 

 scientific standpoint and who have addressed only a 

 scientific audience are less generally known. 



Obviously it would be out of keeping to attempt 

 in a few pages to treat of the various aspects of the 

 large and complex group of insects. Accordingly, 

 only a few selected topics will be brought briefly un- 

 der consideration. 



On account of their relation to the transmission of 

 diseases insects have become of w T orld-wide interest, 

 and those topics are selected that best illustrate their 

 connection with human diseases. These are Malaria, 

 Yellow Fever and Sleeping-sickness. It is to be borne 

 in mind that there are other human diseases trans- 

 mitted through the agency of insects, as bubonic 

 plague, sometimes, typhoid fever, etc., and many 

 animal diseases of cattle, horses and lower animals. 



Malaria. Let us become acquainted with the 



