302 ENTOZOA. 



sliall be compelled to cast aside numerous false teachings which 

 have from time to time been handed down to us. In many cases, I 

 shall not even allude to these vague opinions, but take for granted 

 that the more absurd ones are no longer deemed worthy of credit 

 by any persons who are likely to peruse this volume. 



20. ASOARIS LUMBEICOIDES. 



• 



A. lumbricoides, Linneus ; Bloch ; Goeze ; etc. 



Fusaria lumbricoides, Zeder. 



Lumhricus teres hominis, Tyson ; Redi ; Yalisneri. 



? Nematoideumhominis (ventricuU), J) eglsiiid; Leveille; etc. 



? N. hominis (viscerum), Pruner ; Die sing. 



? Ophiostoma pontierii, Cloquet ; Delle-Chiaje ; Bremser. 



General and Specific Characters. — A nematode helminth resembling the common 

 earth-worm in size and general appearance, the males measuring from four to six 

 inches in length, and the females from ten to fourteen inches ; body smooth, fusiform 

 and elastic, marked by numerous fine transverse rings, and attenuated gradually to- 

 wards either extremity, the anterior terminating in a much produced tri-papillated 

 mouth, the posterior in a bluntly-pointed tail; female much broader than the male, 

 having a diameter of 5 of an inch, and consequently a circumference of f " ; male 

 reproductive organs furnished with a double spiculum or penis, the caudal extremity 

 being otherwise readily distinguished from that of the female by its arcuate form; 

 female reproductive orifice situated towards the lower part of the anterior half of the 

 body, at which point the body frequently bursts after the animal has been placed in 

 water. 



This well-known parasite is by some still considered identical 

 with the Ascaris megalocephala of the horse, and with the Ascaris 

 siiilla of the hog ; but I have long made up my mind that it is a dis- 

 tinct species, in which view I am anticipated by Dujardin, Moquin- 

 Tandon, Claparede, and many other helminthologists. I need also 

 scarcely add that its earth-worm resemblances are very slight, 

 its afiGinities and structural peculiarities being altogether different. 



The naked-eye descriptive anatomy of Ascaris lumbricoides was 

 long ago made out by Cloquet ; and full details were given in his 

 well-known " Anatomie des Vers Intestinaux," from which many 

 particulars were subsequently copied by various writers. In the 



