372 ANIMAL PAEASITES. 



formation. During deposition they came from the vagina, 

 sometimes singly and in the direction of their length, sometimes 

 several together, and even in the direction of their transverse 

 diameter. 



General physiological remarks.. — The locality of these worms 

 is the lower part of the intestinal canal, especially the rec- 

 tum, hut they also pass further into it, and even into the 

 small intestine, at least into its lower regions. Certainly such 

 statements as those of TVulf, Brera, and Bianchi, who profess 

 to have found them in a sac between the membranes of the 

 stomach, in the oesophagus of a woman who had died from linger- 

 ing nervous fever, and in one of the ventricles of the brain, are, 

 as Bremser has already said, observations which no one will 

 believe who has not seen them with his own eyes. Their 

 further wandering within the intestinal canal itself, when the 

 worms are otherwise found living free in it, will surprise 

 no one, as the worms notoriously even wander out of the anus 

 and into the vagina of females, in which, however, they must 

 find a nourishment rather different from the intestinal mucus. 

 Whether they can wander into the urethra of boys or men 

 I do not know. It is a superstition to ascribe them alone or 

 principally to childhood. I was myself consulted by a very old 

 Saxon general on account of these tormentors; a second subject, 

 the most troubled of any of my patients, was between forty and 

 fifty years of age ; and I myself still suffer from them in 

 my thirty-sixth year, and only two years ago expelled from 

 myself a young Ascaris lumbricoides. In short, thread-worms are 

 limited to no age, and to no particular part of the world. They 

 have the privilege over other Helmintha, of being the tormentors 

 of eveiy age and every people. 



The mode of their migration into the human intestine has 

 already been referred to. 



Action, diagnosis, and prognosis. — According to the number 

 of individual worms present, and their position, their actions are 

 various. A few worms scarcely produce any symptoms; nu- 

 merous worms, especially when they are situated in the lowest 

 part of the rectum, make themselves observable by an extremely 

 troublesome itching in the anus and its external neighbourhood. 

 Certain foods, especially carrots, onions, fruits, &c, render the 

 worms particularly restless, and they are then troublesome during 

 the whole day with the itching referred to. In many cases this 



