TOXIC EFFECTS 203 



pany Ascaris infection, but which have usually been attributed 

 to other causes. With such an array of formidable chemical 

 compounds in the body substance of intestinal worms, it is not 

 necessary to search for mechanical factors to explain intestinal 

 disturbances, abdominal pains, nervous and mental symptoms, 

 and the various other apparently unrelated conditions which 

 accompany infection with such worms. When, as in the case 

 of hookworms, such effects are combined with blood-sucking and 

 bleeding from wounds, facilitated by secretions which prevent 

 coagulation of blood, it is not difficult to understand how such 

 profound anemia and loss of vitality are produced by compara- 

 tively few small worms. The presence in blood of toxins ab- 

 sorbed from worms in the intestine is further indicated by changes 

 in the blood itself. The anemia of hookworm disease, due both 

 to reduction of blood corpuscles and to diminution in percentage 

 of haemoglobin, is so well known that anemia is sometimes used 

 as a synonym for hookworm disease. Similar though usually 

 less marked anemia occurs in cases of infection with other worms, 

 e.g., the fish tapeworm, Dihothriocephalus latus, the blood flukes, 

 etc. Another symptom of the presence of worms in the body is 

 a change in number and kinds of leucocytes or white blood 

 corpuscles. An almost universal symptom, though one which is 

 occasionally absent even in the infections in which it is most 

 characteristic, is an increase in the number of so-called " eosin- 

 ophiles," white blood corpuscles containing granules which 

 stain red with eosin. These cells are supposed to be for the pur- 

 pose of destroying toxins in the blood just as some of the leuco- 

 cytes are apparently for the purpose of capturing and destroying 

 bacteria or other foreign cells. The mere presence of an in- 

 creased number of them is, therefore, sufficient reason for as- 

 suming the presence of toxins for them to destroy. The normal 

 number of eosinophiles varies from one per cent to four per cent of 

 the total number of leucocytes, whereas in infections with such 

 parasites as trichina, blood flukes, echinococcus cysts, etc., 

 the number nearly always rises to five per cent or higher, and in 

 some cases reaches over 75 per cent. 



Another factor which is undoubtedly of prime importance is 

 the portal of entry which intestinal worms give to Bacteria and 

 Protozoa. We have awakened to the importance of a '' whole 

 skin " and the danger which accompanies the piercing of it by the 



