848 THE NATURAL HISTOEX EETIEW. 



excused for assigning a new meaning to Hamlet's supposed 

 reference to the earth-worm : " Tour worm {Taenia) is your only 

 emperor for diet ; we fat all creatures else to fat us, and we fat our- 

 selves for maggots {Trichince) ."^ T. medio-canellata comes to us 

 from calves and oxen. Most Entozoa, in the first instance, enter 

 by the alimentary canal. There some remain, and acquire their 

 complete development ; others, including the embryos of these 

 last, pierce the digestive wall, and obtain access to their appropriate 

 dwelling-place, either by direct penetration, or the more ready tran- 

 sporting influence of the blood-current. 



Of Helminth ology, in its relation to pathology and therapeutics, 

 we shall not here treat. It has been shown that some Untozoa give 

 rise to various symptoms of a general or special character, indicating 

 either slight affections or diseases sufficiently serious to end in death. 

 These diseases require medical or surgical assistance, though cases 

 may arise in which, from the situation of the parasites, no remedy 

 can be obtained. Moreover, the diagnosis of the presence of Hel- 

 minths is often very difficult, and sometimes quite impossible. 



And yet it may be urged that scarcely six species of human 

 JEiitozoa produce morbid phenomena sufficiently pronounced or alarm- 

 ing in their nature to merit (in the aggregate) distinct names. 

 Trichina, Bllliarzia, Dracun cuius, the two last extra-European forms, 

 and the various kinds of hydatids are, in this respect, particularly 

 worthy of notice. Even hydatids cannot, in strictness, be said to 

 cause special symptoms ; but rather, as foreign bodies occupying 

 important organs, induce, to a greater or less degree, local mischief. 

 Other worms, occurring in the hollow viscera, may, in like manner, 

 excite irritation. But such irritation is seldom pathognomic. Many 

 Helminths produce no positive symptoms whatever, and the evils 

 ascribed to their presence ought fairly to be attributed to other 

 causes. Thus, to take Tcenia as an instance. AV^hen this animal, 

 in its strobiloid state, occurs as a parasite of the alimentary canal, 

 good authorities inform us that no indication of its existence 

 there can be relied on, save the expulsion of proglottids from the 

 body. "Man may enjoy perfect health through a number of 

 " years, with a ta^peworm in the intestines. We have ourselves 

 " [continues Weinland] known one case of this kind, in our neigh- 

 " bourhood, the person being a butcher. The Abyssinians even 

 " consider it as a sure sign of health to be the bearer of a tape- 

 " worm, and a negro slave among them is valued higher for it." 



