INSECTS INTESTINAL WORMS DIAGRAM 7. 157 



CLASS OF INTESTINAL WORMS. 



Men and animals nourish a large number of parasitic worms in 

 their bodies. They are not always really dangerous to health, 

 except in children : out it is always advisable to get rid of them 

 as soon as possible, and a doctor should always be consulted. 



The Ascaris is the worm which is most commonly found in 

 children. It is much like an earth-worm in shape, and is some- 

 times mistaken for one. But on looking at it, we observe that if 

 it has the same shape, it can neither move so rapidly nor lengthen 

 and contract in the same manner as the earth-worm. The asca- 

 rides live in the digestive tube of animals as well as man. 

 Children contract them more frequently than grown up persons, 

 from their habit of putting in their mouth anything they find, 

 and eating fruit which they pick up on the ground. They often 

 swallow the eggs of ascarides at the same time, which hatch and 

 grow in their stomach. 



The Toenia. This is also called the tape-worm, and it is 

 erroneously supposed that only one can exist in the same 

 person, although several may occur at once, as is indeed often 

 the case. This worm is flat like a ribbon, and is composed 

 of a series of small square pieces attached to each other, which are 

 called rings or segments, in spite of their flat shape. The worm's 

 head is at most not larger than a pin's head ; it is rounded, and 

 exhibits four hollows on the side which are arranged regularly, 



