THE ASCARIS LUMBRICOIDES. 85 



expelled from these situations. It may also find its 

 way into cavities which possess a more or less direct 

 communication with the alimentary canal, or, in con- 

 sequence of the existence of a wound communicating 

 with the intestines, it may reach parts which have 

 naturally no relation to the intestines. 



The number of lumbrici which are present in the 

 same individual, at one time, is very variable ; very 

 often, not more than one or two, or from that number 

 to six or eight, are found ; whilst they are occa- 

 sionally so numerous as to fill and even to distend the 

 intestine ; several cases are recorded, in which the 

 lumbrici amounted to two or three hundred. 



Children are more subject to lumbrici than 

 adults, but these worms are rarely seen in children 

 of less than one year of age ; towards the age of 

 three years these entozoa begin to become common. 

 Women are said to be more frequently affected by 

 them than men. 



The ascaris lumbricoides is developed principally 

 in persons who are of weak, scrofulous constitution, 

 in those who live upon food of a bad quality, or who 

 live chiefly upon legumes, fruit, and milk, or who do 

 not drink fermented hquids, such as beer, wine, &c. 

 The exact extent of the influence of constitution and 

 of diet upon the development of worms has not, 

 however, been yet determined. 



The season of the year appears to exercise some 

 influence upon the development of the round-worms, 

 and most writers are agreed that these parasites are 

 especially common in autumn ; but this opinion has 

 been sometimes based upon the importance which is 

 attached to the use of fruits as a cause of the produc- 



