THE MICROSCOPE. 



SKPTKNIBKR, 1894=. 



Number 21 



New Series. 



Objects Seen Under the Microscope. 

 XVI. — The Crab-Louse. 



[Peu Drawings.] « 



In the order Hemiptera, sub-order Parisita and genus 

 Pthirius is to be found the Crab-louse (Pthirius pubis). 

 The one shown below has been drawn from a photo-mi- 

 crograph made by Dr. W. C. Borden, U. S. N., with a 

 Beck one-inch objective. These offensive creatures af- 

 fect the pubic region and the arm pits of man. They 



cling to the skin and make an irritating puncture in the 

 flesh of the unclean persons upon whom they are pari- 

 sitic. 



" There are four prominent processes on each side of 

 the abdomen, beset with long bristles, the posterior pair 

 being the longest and most slender. It is about three- 

 fourths of a line in length, by one-half a line in breadth. 



