BOTHRIOCEPHALUS LATUS. 103 



excusable, and even the following one must be mildly criticised. 

 What there is good and tenable in it will be seen in the future. 



When Crepiin found Bothriocephali which, as is well known, 

 are extremely rare in all terrestrial mammalia in the cat at 

 Greifswald, the answer to the question, how the cat obtained 

 them, is easily given. This cat certainly got them in the same 

 way as the marine birds of prey, by devouring sea-fishes found 

 upon the shore, or the intestines of fishes, which, especially 

 in sea-port towns, are often left in large quantities by the 

 fishermen, in places where they gut the fish in preparing them 

 for salting or smoking, and which, even in the kitchens of private 

 houses or hotels in those districts which abound in fish, are fre- 

 quently thrown to the expectant cats. A similar process cannot 

 be proved with regard to the Bothriocephalus latus hominis ; for 

 from the intestinal canal of what fish could man derive the 

 Bothriocephalus, as he eats nothing of this kind ? Perhaps the 

 geographical distribution may give us a little clue. I will not 

 discuss the question, whether I have a right to think that the 

 Bothriocephali followed the great expeditions of the migration of 

 peoples from the east, and whether they were introduced by the 

 Mongols and Tartars into Russia and Poland, and thence spread 

 into East Prussia, Finland, Sweden, and Norway ; and by the 

 Arabs and Moors into Africa (Abyssinia and Algeria) and Spain, 

 and thence into the South of France and Switzerland ; but also by 

 the great, and, as it were, local migrations into large commercial 

 towns and emporia (Hamburgh, Rome, Naples). But, never- 

 theless, the present geographical conditions of all these places 

 allow them to be looked at in a common point of view r . They 

 all lie in low situations, on large marshy districts, on the shores 

 of rivers and lakes, or of the sea, and especially in places exposed 

 to inundation. Could the scolex live in a low aquatic or marsh 

 animal, as, for instance, in snails of the smallest kind ? arid could 

 men swallow the latter in any way whilst eating raw salad, raw 

 cucumbers or melons, raw fruit which has lain upon the ground, 

 or raw roots, such as turnips, onions, &c., without either peeling, 

 or, as is frequently done by country people, after peeling them 

 with the teeth ? 



Carl Vogt has stated that we infect ourselves with Bothrio- 

 cephalus by using sewage water, in which the ova from the pro- 

 glottides of this worm which have passed off with the human 

 faeces exist, as a manure for salad. Here the ova remain ; we 



