171 



TRANSLATIONS. 



Experiments on the Migrations of Entozoa. 

 By MM. A. PoucHET a7id Verrier. 



('Comptes rendus,' May, 1862, p. 958.) 



In a work published by one of us in 1859, a close compara- 

 tive examination was made of the doctrines of those observers, 

 who in Germany and Belgium had occupied themselves with 

 the subject of the metamorphoses of the Entozoa and their 

 peregrination through the living organism. The obvious 

 result of this examination was to excite very weighty doubts 

 in every thoughtful mind. M. Davaine, in his remarkable 

 ' Traite des Entozoaires/ also says that the conclusion in his 

 mind, from the agreement in the facts and the divergence in 

 the opinions of the experimenters, was '' that the question 

 still demands sound criticism and fresh researches." 



One observer states that, on nine different occasions, he has 

 succeeded in producing Teenies in the intestine of the dog, by 

 causing it to swallow some Canuri of the sheep. It will be 

 seen that we also have been as successful as this experimenter, 

 and that, in fact, it is the great amount of this success that 

 has given rise to our doubts — we have occasionally reaped 

 more than we have sown. 



But before giving an account of our experiments, let us 

 recal briefly what are the Entozoa upon which they have been 

 instituted. The first is the Ccenurus cerebralis, a vesicular, 

 polycephalous worm, common in the sheep, in which its pre- 

 sence causes the disease termed " staggers." The second is 

 Tania serrata, a cestoid worm, extremely abundant in the 

 dog. 



According to the experiments above referred to, this is 

 what takes place : — The dogs devour the heads of the diseased 

 sheep, and the Canuri are by this means introduced into 

 their stomachs. Having reached this locality, each of the 

 polycephalous helminths separates itself from the parent cyst, 

 elongates enormously, and becomes a Tcenia. The entozoon 

 returns to the sheep in this wise : — When the Tanice of the 



