TRANSMIGRATIONS AND METAMORPHOSES. 245 



certainty that these filamentary bodies are no more 

 animals than the globules of blood, and that all that 

 was thought to have been observed of their organization 

 was nothing but pure fancy. 



The trichinaB, which are now completely known in 

 the minutest details of organization and manner of life, 

 have a distinct mouth, and they have a complete 

 digestive tube with an orifice at each end of the body, 

 like all worms in the form of a thread, which, for this 

 reason, are called by naturalists Nematodes as opposed 

 to Cestodes (in the form of a ribbon or tape). Besides 

 this nutritive apparatus, trichinae, like nematodes in 

 general, have the sexes divided into two distinct indi- 

 viduals, so that there are males and females, which 

 can be easily distinguished from each other by the size 

 and form of the body. 



Trichinae are found in the flesh of almost all the 

 mammals. If we eat this trichinous flesh, the worms 

 become free in the stomach as digestion goes on, and 

 they are developed with extreme rapidity. Each female 

 lays a prodigious number of eggs ; from each of these 

 comes a microscopic worm, which bores through the 

 walls of the stomach or the intestines, and thousands of 

 trichinaB lodge themselves in the flesh, where they hide 

 till they are again introduced into another stomach. 

 When the number is great, their presence may cause 

 disorders or even death. Leuckart's experiments on 

 animals aroused the attention of physicians, and then it 

 was found that patients who had shewn exceptional 

 symptoms, had fallen victims to the invasion of these 

 parasites. Leuckart counted 700,000 trichinae in a 

 pound of the flesh of a man, and Zeuker speaks of 



