82 PARASITES OF MAN 



light of the occurrence of tapeworm, and I have seen many 

 patients who had been told by their usual medical advisers 

 that the presence of the worms was of little consequence. 

 To account for this wide-spread error there is some basis in the 

 fact that by far the majority of infested persons suffer only the 

 trifling inconvenience arising from the passage per anum of the 

 proglottides ; moreover, the less civilised the tapeworm-bearers 

 happen to be, the less are they likely to suffer. The recorded 

 experience of Kaschin, before referred to, where 500 hospital 

 patients, in the Baikal district, had tapeworm, although 

 all of them were being treated for other disorders, affords 

 another argument tending to the same conclusion. On the 

 other hand, amongst Europeans only a small percentage of 

 tapeworm-patients suffer severely. But without trenching 

 upon the symptomatology and prognosis of tapeworm disease, 

 I may remark that I have (in my Manual) summarised the 

 the whole facts of cysticercal prevalence within the compass of 

 two brief propositions: 1. The prevalence or the rarity of 

 Cysticerci in cattle in any given country must be determined 

 primarily by the habits of the people ; for since the beef measle 

 ^an only result from the ingestion by the ox of the eggs of the 

 Tania mediocanellata, it is clear that the degree of infection of 

 cattle will correspond with the facilities- offered by egg-disper- 

 sion. 2. It may be affirmed that the frequency of this particular 

 species of tapeworm amongst the people occupying any given 

 area will bear a strict relation to the amount of underdone 

 measly beef consumed by the inhabitants. 



Another question, and one of great interest to sanitary 

 science, is that which I have raised in reference to the period 

 that nature requires for the destruction of the Cysticerci, or, in 

 other words, for the performance of a natural cure by calcareous 

 degeneration of the parasites. I have shown that all kinds of 

 tapeworm larvaB (measles, bladder-worms, ccenuri, and so forth) 

 have a natural life-epoch assigned to them, and in one of my 

 experiments on a Dutch heifer or young cow I demonstrated 

 that a period of ten months was more than sufficient to ensure 

 the perfect destruction of the Cysticerci of cattle. Moreover, 

 this law or process of natural cure is not limited to cestode 

 parasites, but affects all other kinds of internal parasites in one 

 or other of their juvenile stages of growth. In the flesh of my 

 experimental animal I estimated that there were not less than 

 12,000 of these degenerated Cysticerci. This positive contribu- 



