168 Dr. O^Bryen Bellingham on Irish Entozoa. 



( Ascaris megalocephala* (Cloqaet). f^m2i\\ intestines of horse 



^- I Equi (Turton) \ (Equus Cahallus). 



"Caeca of partridge (^Perdix cinered). 

 Caeca of quail ( Perdix Coturnix), 

 Caeca of pheasant (Phasianus Colchicus). 

 vesicularis\ -^ Caeca of chicken (Gallus domesticus) . 



Cae.:a and rectum of shieldrake (Tadorna Bel- 



lonii). 

 ^Caeca of peacock {Pavo cristatus). 



common : this species is more frequently met with in early life than 

 in the adult, and is said to have been found in one-fifth of the indi- 

 viduals examined between the iages of three and ten ; it is very rare 

 in old age. In ninety cases in which I examined the intestinal canal 

 of patients who died in St. Vincent's Hospital, Dublin, I found this 

 species only twice, and then only a single specimen; the subjects were 

 both adults ; of these ninety cases however only five were under ten 

 years of age, the period at which this species is most frequent. The 

 Ascaris lumhricoides occurs sometimes in considerable numbers, and 

 its size is in general in an inverse ratio to the number which exist in 

 the same individual. The penis of the male is very frequently found 

 projecting ; it is double, and it appears strange that so accurate an 

 observer as Cloquet should have described it as being single. 



* The Ascaris megalocephala (Ascaris Equi of Turton's ' British 

 Fauna') is a common inhabitant of the small intestines of the horse, 

 and was considered by many to be identical with the Ascaris lumhri- 

 coides, until M. Jules Cloquet (in a memoir which obtained the prize 

 of the Royal Academy of Sciences of Paris in the year 1818) pointed 

 out several material particulars in which it differs from it, and being 

 satisfied that it is a distinct species, he named it Ascaris megaloce- 

 phala, from the large size of the tubercles which surround the mouth ; 

 indeed any one who places the two species side by side must be 

 struck with their dissimilarity. Thus the body of the Ascaris mega- 

 locephala is much thicker in proportion to its length, and the tuber- 

 cles surrounding the mouth are considerably larger than in the As- 

 caris lumhricoides. The vulva and the circular depression upon the 

 body of the female are nearer the anterior extremity, the vagina is also 

 longer, and the intestinal canal much larger than in the Ascaris lum- 

 hricoides. 



t The females of the Ascaris vesicularis from the caeca of the do- 

 mestic fowl resemble the female Ascaris vermicularis of the human 

 subject, the posterior extremity being subulate ; in the males it is 

 obtuse, terminates in a short mucro, and the body at this part ap- 

 pears to be edged by a lateral membrane. The penis, apparently a 

 single filament, projected externally in all. 



The specimens of Ascaris vesicularis from the pheasant agree with 

 Rudolphi's description of the species, except that in the females the 

 body has a greater diameter anteriorly than posteriorly. The ante- 

 rior extremity is inflexed, the , concavity towards the abdominal sur- 



