DE. T. SPENCER COBBOLD ON STBON&TLTJS AXEI. 261 



presence of maw-worms, yet it is quite certain that other animals 

 do suffer, not excluding the ass's congener, the horse, which 

 not unfrequentlj develops gastric growths due to Spiroptera 

 megastoma. In one case rupture and death ensued. 



Apart from all practical considerations, the new parasite from 

 the ass helps to throw light upon questions of morphology. In this 

 connection it may be permitted me to add that the singular maw- 

 worm described by me from the hog (Simondsia paradoxa, Cobb.) 

 is by far the most remarkable nematode infesting vertebrates. 

 Since my paper appeared in the Society's ' Transactions ' (2nd 

 ser. Zool. vol. ii. part 8) Professor Schneider has, at my request, 

 been good enough to examine two examples, male and female. 

 Whilst correcting me in some particulars of detail, he appears to 

 think that I have even underrated the value and significance of 

 the find both in its morphological and zoological aspects. His 

 conception of a possible rhizocephalous relation, however, would 

 be more readily convincing if there were in Simondsia any signs 

 of retrograde metamorphosis, apart from the existence of a large 

 protective " rosette " or sac-covering of the uterine tubes, which, 

 as in SacGulina, acts as an organ of anchorage *. 



* Prof. Schneider, in a letter to me, says : — "The male Simondsia possesses 

 two unequal spicula and four pre-anal papillae. Accordingly the Simondsia 

 would belong to the genus Filaria, in my system of Nematoda ; and according to 

 Eiudolphi's system, to 8piro]}tera. It seems to me, however, to be different 

 from Spiroptera strongylina, Eud. {Filaria strongylina, mihi), and that it 

 cannot be looted upon in the light of a developmental condition of Filaria 

 strongylina. 



" The remarkable sac-like protrusion contains (as you have discovered and 

 as I hare convinced myself) the chief mass of the sexual organs and an extension 

 of the intestine. I venture, however, to remark that I do not believe the 

 protrusion to be an inversion of the uterus, as it proceeds directly from the 

 skin. It is an outgrowth from the integument, for one can plainly see that 

 the diagonal lines of the skin, which are always present in Nematodes, also pass 

 on to the protrusion (Ausbuchtung), the passage of the body-skin on to the 

 protrusion being everywhere a gradual one. According to my interpretation the 

 vulva lies not in the protrusion itself, but in front of the same. Yet I dare not 

 affirm this with certainty, on account of the difficulty of examining a single 

 example which has been so long preserved. 



" The Simondsia would thus not connect itself with Sphmrularia, but would 

 serve to demonstrate a hitherto unknown and very remarkable modification of 

 the Nematode-body. The importance of your beautiful discovery would be 

 thereby only increased. According to my belief, Simondsia exhibits in the 

 embryo and larval condition, and probably also at first in the sexually mature 



lilNN. JOITBlSr. ZOOLOGY, VOL. XIX, 21 



