194 ANIMAL PA11ASITES. 



in which time, however, I have always found it immature. For 

 the size of the hooks vide infra. 



Eygs and six-hooked embryos. — There can he no doubt that 

 these little creatures must occur at some period in the intestines 

 of man, getting there with drinking-water, or with raw articles 

 of diet, which have been derived from a damp soil, and which 

 we have already mentioned several times, such as salad, straw- 

 berries, roots, turnips, and fallen fruits, especially such as 

 have been collected after a wet day and eaten raw with the 

 peel on. 1 Like the embryos of the other Taniee, however, they 

 escape the human eve on their entrance into the human bod v. 

 Their migration itself is certainly performed like that of the 

 other embryos of the Tanue, by their perforating the intestine 

 and getting into the abdominal cavity, where they prefer attaching 

 themselves to the liver or the kidneys, or to the organs lying in 

 the thoracic cavity. A portion of them, however, may migrate 

 along the ductus choledochus to the outer surface of the liver. In 

 the spot which they select they take up their position in the 

 same way as the other Cestodea, and the envelopes formed round 

 them have the same properties as with the latter, but are, never- 

 theless, distinguished by the thickness of their walls. 



Scolex. — I have never had an opportunity of seeing this scolex 

 with certainty in the human subject, although I have repeatedly 

 seen it in pigs and sheep. It has certainly been seen by Gescheidt 

 in the eye, and by Eschricht. I shall therefore treat of this 

 worm here in accordance with Eschricht' s interesting communica- 

 tions, with additions which I shall take the liberty of making 

 from my own observations on this creature when found in animals. 

 There can be no doubt that Eschricht has seen it, and I here quote 

 from his memoir already cited, all that refers to a consumptive 

 Danish miller's man (1. c, pp. 15 — 16) who suffered from Echino- 

 coccus. Schleissner's two Icelandic cases belong to b. 



The scolex forms a vesicle which can hardly exceed the size of 

 a large apple. According to Eschricht, it measures 2\ — 3 inches, 

 and forms a firm attachment to the organ in which it dwells. 

 The anatomical elements are the same as those of all enveloping 



1 The common people, as is well known, say that tape-worms are acquired by eating 

 apples, and especially the so-called bloom on ripe apples. I have already shown the 

 impossibility of this supposition, but I must admit that an infection with cystic worms 

 of all kinds by eating raw windfalls with the skin on is certainly possible. 



