280 THE ROUND WORMS 



transverse rings and resembles Ascaris but is more white in color. It is said to be 

 not uncommon in southern Russia. 



The Echinorhynchus or Gigantorhynchus moniliformis might be contracted 

 by persons eating death-watch beetles as is sometimes done for the improvement of 

 the complexion. 



HIRUDINEA (LEECHES). 



Hirudo medicinalis. This is the leech used medicinally for the abstraction of 

 blood. They have a secretion which prevents coagulation of the blood so that when 

 they are removed the wound still continues to bleed. 



Limnatis nilotica. This species has been found in many parts of Northern 

 Africa and, gaining access to the stomach through drinking-water, it wanders to 

 the pharynx, nares, and even trachea. Manson refers to a case of obstinate epis- 

 taxis and headache caused by a leech in the nostril. 



This leech is about 4 inches long (8 to 10 cm.) and about 1/2 inch (1.2 cm.) 

 broad. The dorsal surface is greenish brown with narrow orange brown borders. 

 The young leeches are only about 1/8 inch ( 3 mm.) long and taken in with the drink- 

 ing water may attach themselves to the surface of some mucous membrane and after 

 some weeks reach adult size. 



Haemadipsa ceylonica. Whese are land leeches found in India, Philippines, 

 Australia, and South America. They are only about i inch (25 mm.) long and are 

 slender. They leave the damp earth to climb shrubs and from there to drop on 

 animals or man passing through the forest. The bites are painless, but may be fol- 

 lowed by ulcers. They may get into the nostrils. 



They will even penetrate thick clothing in order to reach the skin. 



