74 BOARD OF AGRICULTURE. 



To prevent measles in hogs they should not be allowed to have 

 access to human excrement, the reverse of which is too often 

 specially provided for by farmers. To avoid the same para- 

 sites in our own flesh we must take care to have all fruit and 

 other uncooked vegetable food well washed and our drinking 

 water pure. 



Tlie Beef Tape-worm of Man ( Tcenia mediocanellata Kuch.) ; 

 and its young, the " measles'^ of veal and beef. 



This is a very large species, which was formerly generally 

 known as the unarmed variety of the human tape-worm. It 

 is known to occur among all beef-eating people, and is the 

 common species in Africa, Western Asia, and several European 

 countries, especially in Austria, Turkey, and certain parts of 

 Eussia. 



It has long becyi known that Jews, Mohammedans, and other 

 people who never eat pork, are nevertheless liable to be in- 

 fested by tape-worms. It was also observed, many years ago, 

 that infants fed upon dried beef — a custom much practised at 

 St. Petersburg — were liable to have the same parasites ; and 

 these facts were formerly brought forward as arguments 

 against the doctrine that the common tape-worm is derived 

 from eating the larval form contained in measly pork. But 

 it was soon discovered that nearly all the tape-worms obtained 

 from patients in Mohammedan countries, as well as in Austria, 

 and some other parts of Europe where pork is little used, were 

 destitute of the two circles of peculiar hooks around the cen- 

 tral, proboscis-like prominence of the head, as well as the 

 prominence itself, which are very conspicuous features in the 

 common tape-worm of pork-eating people. Owing to these 

 peculiarities, naturalists began to consider the two forms 

 either as different varieties or different species. The source 

 of the unarmed tape-worm remained uncertain, however, until 

 direct experiments were undertaken by Leuckart, Mosler, and 

 others to settle this question. Thus it was discovered that 

 when the joints or eggs of the unarmed tape-worm (^Ta'nia 

 mediocanellata^ were given to calves, the eggs hatched in the 

 stomach, and tlie young embryos worked their way, by means 



