316 ENTOZOA. 



CHAPTER XI. 



ASOAEIS MTSTAX. 



The author's discovery of the occurrence of Ascaris mystax as a human parasite — 

 General and specific characters — Vindication of the accuracy of the statements of 

 Irish naturalists — Cases by Belliagham, Pickells, Scattergood, and Leuckart — 

 Structure and development — General and specific characters of Trichocephalus dispar 

 — Organization — Remarks on Filaria lentis and F. trachealis. 



I GLADLY, in the first instance, embrace the opportunity of again 

 attempting to rescue from oblivion a most important contribution 

 to belminthological literature. I here propose to repeat and amplify 

 those proofs which I have previously advanced in the view of 

 establishing a recognition of the fact that the common Ascaris mys- 

 tax of the cat is liable to infest the human body. This position I 

 have worked out independently ; but I am none the less happy to 

 learn, from the lips of Professor Leuckart, that another case of this 

 kind occurred in Germany about two years ago. I think I under- 

 stood him to say that the worms were readily recognized as 

 specimens of Ascaris mystax. At all events, from what is stated 

 in the sequel, it is quite evident that aU who allowed Bellingham's 

 Ascaris alata to be a parasite of some kind or other, regarded it 

 as a new species. Not one single helminthologist ever stated that 

 the parasite in question was really referable to the Ascaris 

 mystax, but Dr. J. V. Thomson thought that it resembled that 

 species. Many years ago, when I accidentally stumbled upon 

 Pickell's figure, I at once regarded it as a representation oi Ascaris 

 mystax, and from that time forth I resolved to work out the subject 

 whenever an occasion might offer itself. Thanks to the kindness 



