86 ANIMAL PAEASITES. 



towards the centre. The'micropyles, 100 in number, and distant 

 from each other -^" , form extremely narrow canals (jgg/"), which 

 pass inwards from the screen, open then, and exhibit a longitu- 

 dinal ridge of ^" on the inner surface of the screen. Externally 

 these micropylar openings form .clefts, which occur upon the 

 anterior clavate extremity. 



Even in the eleventh century, bugs were naturalised in Stras- 

 burg, so that they did not come to us from America. Very 

 plentiful in the north of Russia, they are not found in South 

 America, New Holland, and Polynesia. They are so difficult to 

 extirpate because they can bear hunger for years, and also a great 

 degree of cold. They live on the blood of man, and attack him 

 particularly at night, after leaving the joints of the woodwork and 

 walls, the crevices in the paper, and the grooves in the bedsteads, 

 in which they lay their eggs everywhere ; they also harbour in 

 clothes. 



The wounds produced by their bite are distinguished by the size 

 of the resulting spots, and by their troublesome itching. In their 

 centre, also, we may detect a pierced canal, by the aid of the lens. 

 It is certainly possible that in doubtful cases the diagnosis may 

 be rendered more certain by the smell, and by the examination 

 of blood- spots in the bed-linen, from which we might probably 

 be able to evolve the characteristic odour of bugs by solution in 

 water and treating with acids, but we get at the bottom of the 

 affair still better by the examination of the bedsteads, &c. 



Treatment. An immense number of tinctures and secret 

 remedies are sold against bugs, of which, according to Poppig, no 

 single one will prove efficacious, although a combination of several 

 may do so. In this case, also, I have seen very good results 

 from the Persian insect-powder, the price of which is now greatly 

 reduced. It is sprinkled in the joints of the woodwork and walls, 

 the bedsteads, mattresses, &c. It is as well, however, in places 

 where the bugs are very plentiful, to repeat the sprinkling of the 

 powder from time to time, and at all events regularly at the 

 beginning of spring and the approach of autumn, or shortly before 

 the winter torpidity and at the time of waking therefrom, as in 

 such places the larvae in the eggs may perhaps escape the action 

 of the powder. Care should also be taken, that the brood should 

 be sought out and destroyed wherever they can be got at in their 

 hiding-places. 



