38 THE INTERNAL PARASITES OF 



tapeworm known as the Tcenia medio canellata, it is clear 

 that the degree of infection of these animals will 

 correspond with the facilities offered for egg-dispersion. 

 In like manner it may also 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 and veal consumed 

 by the inhabitants. 



These two propositions form the counterpart of each 

 other; and unless we happen to possess an almost 

 unlimited belief in the doctrine of heterogenesis, or 

 spontaneous generation, there is no escape from the 

 well-established truth hereby enunciated. In short, only 

 those persons whose minds are still embarrassed by 

 preconceived opinions, based on conclusions handed 

 down by the ignorant, can have any difficulty in accepting 

 so obvious a general statement of results. It is quite 

 possible that further researches may show that other 

 bearers than calves and oxen may be capable of har- 

 bouring the beef measle. Yet, even should this turn out 

 to be the case, the force and truth of the proposition in 

 question would not be disturbed in the slightest degree. 

 If it should further be shown that in some countries 

 where this characteristic tapeworm abounds, the beef 

 measle is either little or altogether unknown — as happens, 

 for example, in Abyssinia — then the reply to these 

 doubters is to the effect that the larval tapeworm has 

 seldom or never been sought for; and manifestly so, 

 because the relations subsisting between the two forms 

 of one and the same parasite have hitherto failed to 

 attract the attention of the parties concerned. 



Whilst with satisfaction I recognise the increased 

 interest taken in this subject by our professional 



