.PARASITES OE SWINE. 



977 



Fig. 1308.— Section of the Heart of 

 Measly Pig. 



hundred and thirtieth of 

 an inch in breadth, whfch 

 lives rolled up in flesh, 

 and is called Trichina 

 Spiralis. 



The existence of the 

 trichina in human flesh 

 was first discovered in 

 the year 1832, in the dis- 

 secting room of a Lon- 

 don hospital. It was 

 recognized as a new 

 worm by Prof. Owen, of 

 the British Museum, who 

 gave it the name of tri- 

 , china, because as thin as 

 a hair ; he added the 

 specific name of spiralis, 

 on account of the man- 

 ner in which the worm is 

 coiled up in the cyst. 

 " We owe to Leuekart and 

 Virchow our knowledge 

 of the development of these worms in the body of the pig 

 and in man. 



Trichinae are found 

 in the flesh of nearly 

 all the mammals. If 

 any of this trichinous 

 flesh- is eaten, the 

 worms become free as 

 digestion goes on. 

 They develop with extreme ra- 

 pidity. Each female lays' a pro- 

 digious number of eggs. From 

 each of them comes a little worm, 

 which bores through the walls of 

 the stomach or of the intestines, 

 and buries itself in the flesh, 

 where it lies hidden until it is 

 introduced into another stomach. 

 Fig. 1310.— Immature Female Trichina Leuekart counted frOO.000 tri- 



Fig. 1309. 



Sexually Ma 

 ture Male Tri- 

 china. 



