REPEATED EXPERIMENTS ON THE CALF. 467 



phenomena which clearly indicated an inflammatory state, appearing 

 as the result of the experiment. 



I also succeeded in bringing the bladder-worms of Tcenia saginata 

 to development in the calf, and in watching the various stages up to 

 complete maturity. The hitherto often disputed distinctness of the 

 species was undeniably established, and one of the most important 

 sources of human food the ox was shown to be the intermediate 

 host of the most frequent and most widely distributed tape-worm. 

 At the same time it was experimentally established that the abundant 

 importation of tape-worm eggs containing embryos into the ox 

 occasioned a dangerous, and, under some circumstances, fatal disease, 

 which might, on anatomical grounds, be justly designated " acute 

 cestode tuberculosis." 



Considering the enormous import of these facts to Helminthology, 

 hygiene, and pathology alike, it is not surprising that my experiment 

 was abundantly repeated by helminthologists, physicians, and espe- 

 cially by veterinarians. Similar investigations have been made on 

 several animals by Hosier (1864), Boll (1865), Gerlach (1869), Ziirn 

 (1871), Zenker (1872), Probstmayr (1879), and in England by Simonds 

 and Cobbold (1865 and 1866), in Belgium by the younger van Beneden 

 (1879), in France by St. Cyr (1873), as well as by Masse and 

 Pourquier (1877), and in Italy by Perroncito (1877). 



With very few exceptions, these experiments yielded a positive 

 result. The exceptions include only an experiment made by Simonds 

 and Cobbold, 1 and a double experiment made by Klichenmeister, 

 Haubner, arid Leisering, which I do not count, since the maturity of 

 the proglottides was not ascertained, and since they were, in one case 

 at least, decidedly unripe. The calves or oxen under experiment all 

 became diseased with more or less striking, and often fatal, symptoms, 

 and exhibited on dissection numerous bladder-worms in the muscles, 

 and often in the viscera. These represented the results of the feeding 

 at various stages of development, but many of them were frequently 

 dead. They numbered usually many thousands, and in one case 

 where they had all perished at an early stage of development, they 

 were estimated by Simonds and Cobbold at about twelve millions. In . 

 this case, indeed, about four hundred proglottides had been given to 

 the animal within two months, which had, however, in spite of their 

 number, only a comparatively slight illness. 2 



1 Kiichenmeister is mistaken in saying that Gerlach's experiment was without result 

 ("Parasiten," second edition, p. 153). See Bericht d. Thierarzneisch. Hannover, p. 70, 

 1869, where it is expressly noted that the calf, which was killed five months after feeding, 

 was "penetrated through and through with bladder- worms." 



2 Journ. Linn. Soc. (Zool.), vol. ix., pp. 170, 1868. 



