334 THE ANIMAL PARASITES OF MAN 



The development of Cysticercus cellulosce takes two and a half to three or four 

 months ; it is not known how long the cysticerci remain alive in animals ; not uncom- 

 monly they perish at earlier or later stages, and become calcified or caseated. 

 Extracted cysticerci die in water at a temperature of 47 to 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, also the effect of cold on them for some time in cold chambers of slaughter- 

 houses is not lethal, but freezing is fatal (Ostertag). 



There is not the least doubt that human beings are almost exclu- 

 sively infected with Tcvnia 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, mainly, as a 

 matter of fact, deer and wild boar. 



The frequency of cysticerci in pigs' flesh has considerably decreased since the 

 introduction of meat inspection ; in the Kingdom of Prussia there was on an average 

 i infected pig to every 305 slaughtered between 1876 to 1882 ; from 1886 to 1889, there 

 was i to 551 ; from 1890 to 1892, 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( l m J 896 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 with the total slaughtered was as follows : 



In the district of Manenwerder ... ... ... ... i 



Oppeln... ... ... ... i 80 



Konigsberg ... ... ... ... i 108 



,, Stralsund and Posen 



,, Danzig, Frankfort a. O. and Bromberg 



As compared with the district of Arnsberg... 

 Coblenz ... 



, ,, , Diisseldorf 



Miinster and Wiesbaden 



187 

 250 

 865 



975 

 1,070 

 1,900 



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

 eastern provinces, on the other hand, i : 604. Even more unfavourable are the pro- 

 portions in Russian Poland (over i per cent, of pigs measly), in Prague (over 3 per 

 cent.), in Bosnia and Herzegovina (6 to 7 per cent). The cause for this is most 

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

 in the farmyards of the small farmers for the whole day, or allowed to wander in the 

 village streets and pasture lands, they are more liable to take up the oncospheres of 

 the T. solium than when shut up in good pig-styes. 



The geographical distribution of T. solium generally corresponds 

 with that of the domestic pig and the custom of eating pork in any 

 form insufficiently cooked or raw. There are, or were, some isolated 

 districts in Germany, France, Italy and England where the "armed 

 tapeworm" was frequent (for instance, Thuringia, Brunswick, Saxony, 

 Hesse, Westphalia, whereas it is and was very scarce in South Ger- 

 many) ; it is thus easily understood why it occurs very rarely in the 

 East, in Asia and in Africa, in consequence of the Mahommedans, 



