70 HALF HOUKS WITH INSECTS. [Packakd. 



which the current is continued with increasing rapidity by 

 means of the pulsation of tlie pumping ventricle and the 

 powerful peristaltic movement of the digestive tube." Fig. 

 55 shows this tube and adjacent parts of the head magnified 

 one hundred and sixty times ; aa the end of the head ; bb the 

 chitinous band, and c the base of the under lip ; d the under 

 lip protruded, with the hooks ee ; and / the sucking tube, 

 with a few blood disks passing through it. 



How a louse breathes is perhaps as practical a question 

 as how it bites. All insects inliale air through a row of 

 holes (stigmata) in the side of the body, which connect by a 

 series of tubes (tracheae) within, ramifying throughout the 

 body ; no air is taken in through the mouth. Now grease 

 and oil, when in contact with the sides of the body, tend to 

 close up these breathing holes, and then the creature suffo- 

 cates. Thus oil or pomatum is an antidote. A woi'd to the 

 wise is sufficient. 



Not only personally, but also indirectly, through those 

 kinds which swarm on his domestic fowls and quadrupeds, 

 is man affected by these creatures. Those species which 

 live for the most part on birds have true jaws, enabling 

 them to nibble and thus irritate the skin of their host. 



While we are upon this harassing theme we should not 

 pass over that kindred subject the bed-bug. This insect, 

 with a body so flat that an ordinary punch with the thumb 

 only seems to tickle it, seems preordained for a life in cracks 

 and crannies. First noticed in literature by Aristotle, 

 it was also mentioned by Dioscorides and Pliny. It was 

 first met with in Germany in the eleventh or twelfth century, 

 and was mentioned as an English insect by Mouffct in 1503. 

 It is possible that its original haunt was the nests of doves 

 and swallows ; and the most effective way, should it seem 

 desirable to ensure an abundant harvest of these pests, is to 

 keep a number of these birds about our houses. Whether it 

 actually lives under the feathers of doves or not could be 



6 



