T^NIA SOLIUM 



237 



and monkeys (Macacus cynomolgus), and thus transform them into 

 taenise ; the attempts, also, to' infect dogs with cysticerci were 

 likewise, as a rule, abortive. 1 



The development of Cysticercus celluloses takes two and a half to 

 three or four months ; it is not known how long the cysticerci remain 

 alive in animals ; not uncommonly they perish at earlier or later stages, 

 and become calcined or caseated. Extracted cysticerci die in water at a 

 temperature of 47-48 C., in flesh at normal temperature they remain alive 

 for twenty-nine days or more. On account of the present rapid means of 

 pickling and smoking meat the cysticerci as a rule are not killed, but the 

 effect of cold on them for some time is certain death (Ostertag). 



There is not the least doubt that human beings are almost 

 exclusively infected with Tcenia solium by eating pork containing 

 cysticerci, in a condition that does not endanger the life of the 

 cysticerci. The infection may likewise be caused in man by eating 

 the infected meat of other animals subject to this species of bladder 

 worm, though practically this means of infection only occurs excep- 

 tionally in consequence of the rarity of Cysticercus cellulose in the 

 stag, sheep and dog. 



Pigs, on the other hand, are much more liable to be affected with 

 cysticerci, but the conditions have considerably improved since the intro- 

 duction of official inspection of cattle and meat ; in the Kingdom of Prussia 

 there was on an average one infected pig to every 305 slaughtered between 

 1876-1882 ; from 1886-89, there was i to 551 ; from 1890-92, there was 

 i to 817 ; in 1896, i to 1,470, and in 1899, i to 2,102 ; in the kingdom 

 of Saxony in 1894 there was i infected pig to every 636; in 1895 there 

 was i to every 2,049, an d m 1896 only i infected pig was found of 5,886 

 slaughtered. In South Germany pigs with cysticerci are very rare, but are 

 more frequent in the eastern provinces of Prussia ; in 1892 the number of 

 infected pigs compared to the total slaughtered were as follows : 



In the district of Marienwerder . . . . . . i : 28, 



Oppeln .. ..i 



Konigsberg . . i 



Stralsund and Posen . . . . . . i 



- ,, Danzig, Frankfort a. O. and Bromberg . . i 



as compared with the district of Arnsberg . . . . i 



Coblenz .. i 



Diisseldorf . . . . . . i 



Miinster and Wiesbaden i 



80, 

 108, 

 187, 

 250, 

 865, 



975, 

 1,070, 

 1,900. 



The average for the whole of Prussia in the same year was 1:1,290, for 

 the eastern provinces on the other hand, i : 604. The cause for this is 

 most likely attributable to the manner in which the pigs are kept. When 



1 According to Gerlach only young pigs (up to six months old) are capable ot 

 infection, and perhaps the failures may have been due to the anima.ls chosen 

 for experiment being of the wrong age. 



