45 



harm under any circumstances ; and, if the characteristic 

 symptoms disappear, then for all practical purposes the 

 diagnosis is complete, whether the worms have been noticed 

 in the stools or not. 



Difficulty of Finding Oxyuris. 



For the worms are not by any means easy to detect ; and 

 the fact that they cannot be seen in the stools with the naked 

 eye must not be taken as establishing a definite negative. 

 From their extremely small size, the oxyurides are most 

 difficult to discover, when passed per rectum into the faeces. 

 Moreover, it is their habit, when so passed, to plunge instantly 

 below the surface, provided the faeces are sufficiently soft 1 , 

 .and thus lose their distinctive colour. Generally a lens must 

 be used in searching for Oxyuris ; while their eggs are so 

 extremely minute, that they are rarely discovered, unless 

 elaborate measures have been taken to isolate them. 



Method of Search for Adult Worms. 



The adult worms, if present, can be discovered with absolute 

 certainty by a laborious method, described by many helmin- 

 thologists, who do not disguise the distaste with which they 

 carried it out. The suspected stools are placed on a strainer, 

 made of muslin or soft cloth. If necessary, they may be 

 dealt with in successive portions. Water is then poured over 

 them, and the faeces stirred up with a small stick. All the 

 faecal matter breaks down in this process, and passes through 

 the strainer ; whilst the worms, if any, are left behind. 



Method of Search for the Eggs. 



To discover eggs, the microscope must always be brought 

 into requisition. A very small portion of faeces is mixed with 

 water on a glass slide, and such preparations are examined 

 .successively, with the low power, until the eggs can readily 

 be seen. 



Diagnosis from Symptoms. 



Failing the discovery of worms or eggs, there is on orthodox 

 lines no other certain sign of the disease ; but, as few medical 



1 " Si les feces sont liquides, voit qu'il cherche a s'enfoncer dans 

 on voit s'agiter avec vivacite les les matieres stercorales. " (FiEVET, 

 deux extremites. . . . Souvent on J. C., op. cit., p. 17.) 



