198 ANIMAL PARASITES. 



Symptomatology. — Single cysts of this Echinococcus will 

 scarcely produce n.x\y symptoms during life, as the growth of this 

 species appears, on the whole, to be rather limited. I have never 

 yet seen a cyst of this species, in an animal, which had attained 

 the bulk of a large apple, or of a goose-egg. The vesicles are 

 generally of the size of a walnut or a duck's egg, and they project 

 but little, or scarcely at all, above the level of the liver. For 

 this very reason their diagnosis in man presents the greatest dif- 

 ficulties. The disturbance in the functions of the liver will in 

 general be small, and only become more considerable when a 

 great number of such vesicles inhabit the liver, their injurious 

 influence becoming more striking by their increased numbers. 

 The right hypochondiium and the cardia are sometimes painful 

 on pressure, and rather more dulness is exhibited over the liver 

 as far as an inch and a half and more below the false ribs and 

 over the cardia, with irregular evacuations and symptoms of 

 jaundice. 



Pathological anatomy . — The liver is swollen, particularly behind, 

 pale, of a uniform, grayish-brown colour. On its surface it presents 

 larger or smaller spots of a whitish-yellow colour, and of a more 

 or less regular form, generally but slightly raised in this species 

 above the surface of the liver, although there may be exceptions 

 to this in the case of very much enlarged vesicles. On the 

 whole, therefore, the resistance to the pressure of the finger and 

 the feeling of fluctuation are but small, and I also believe that 

 the sensation of the so-called hydatid -buzzing is never to be felt 

 here. This species, as will have been seen already from this 

 description, has its seat too deep in the parenchyma of the liver 

 to project above the level of its surface. 



By closer attention hereafter, we shall certainly often meet 

 with this species of Echinococcus in the human subject, and con- 

 vince ourselves that many of the cases described in literature up 

 to this time referred to this species. But what would be the 

 use of attempting to criticise the old materials in this manual? 

 It is sufficient for us to have called attention to the occurrence of 

 this species in the human body, and to bring forward from the 

 literature of the subject the two interesting cases, namely, the 

 case observed by Von Ammon-Gescheidt, of the occurrence of 

 Echinococcus hominis between the choroid coat and the retina, 

 which refers to this species, and Moller's case. 



a. Von Amnion's case. — The eyelids and the parts surrounding 



