242 ANIMAL PARASITES AND MESSMATES. 



generation which descends from these is distinguished 

 by being of a much smaller size. 



The name of Trichocephalus has been given to nema- 

 todes which have the cephalic extremity very thin, and . 

 ending in such a fine point that it is difficult to discover 

 the mouth. The Trichocephalus of man (Fig. 68) is a 

 curious nematode, which was discovered by a student at 

 Gottingen, in 1761. It is usually found in the caecum, 

 in which more than a thousand have been met with 

 together. The female is from 40 to 50 millimetres long, 

 the male about 37 millimetres. A female Trichocep&alus 

 affinis having laid her eggs in an aquarium, the whole of 

 the contents were introduced into the stomach of a lamb, 

 seven months afterwards, and the walls of its intestines 

 became infested with trichocephali. 



No animal at any time has attracted so much atten- 

 tion as that little worm which lives in flesh, rolled up ; 

 it is about the size of a millet seed, and was found by 

 chance in the dissecting-room of a London hospital, some 

 forty years ago. The plague and the cholera did not 

 inspire so great fear, and this fright had almost passed 

 from Germany throughout the rest of Europe. We were 

 hot among those who wished to take measures at all 

 hazards against the invasion of this worm, since nothing 

 induced us to believe that more trichinae existed then 

 in Belgium than in ordinary times. These measures 

 would have produced no other effect than uselessly to 

 disturb the minds of the public. 



Trichiniasis, which was the name given to the disease 

 caused by these worms, reminds us of tarantism, that is 

 to say, the effects produced by the bite of the tarantula. 

 Mons. Ozanam wrote an interesting work on this subject.. 



