SOLIDUNGULA 379 



hog. The equine Ascaris may occur in any part of the alimen- 

 tary canal, but the small gut forms its proper head- quarters. 

 The entire course of development of this worm has not been 

 traced ; nevertheless, Heller found human lumbricoids measur- 

 ing less than the eighth of an inch. It is not likely that any 

 intermediate host is necessary for the growth of the larvae, prior 

 to their access to the definitive host. I have reared the larvae 

 in impure water and in moist horse- dung, up to the size of ~ of 

 an inch. They were then furnished with a completely-formed 

 digestive apparatus. Davaine kept the intra-chorional embryos 

 alive in water for five or six years. His experiments on rats, 

 dogs, and on a cow, led to no decisive results ; but it is impor- 

 tant to know that the eggs of lumbricoids effectually resist 

 dryness. According to Davaine, however, embryonal develop- 

 ment is thus arrested (except in Ascaris tetraptera of the 

 mouse). 



Seeing how readily the most ordinary attention to cleanliness 

 must suffice to prevent lumbricoid helminthism, it is scandalous 

 that so many severe cases of disease from this source should 

 ever and anon turn up and be reported. In no properly con- 

 ducted stable are these large entozoa ever to be seen in any 

 considerable numbers ; for so long as the water-supply is good 

 and the fodder clean there is no possibility of infection. A 

 fertile source of infection, however, results from allowing horses 

 to drink at foul road-side ponds and from open waters in the 

 vicinity of stables and paddocks where foals are reared. Into 

 the clinical bearings of the subject I do not enter, but a host 

 of interesting records of lumbricoid disease may be found in 

 veterinary journals, both home and foreign. These have their 

 counterpart in the very similar cases recorded in the medical 

 journals, and quoted by me in the 34th bibliography of this 

 work. From Sonsino's report these worms do not appear very 

 common in Egypt, but the veterinary inspector, Dr Zunhinett, 

 had occasionally met with them. From Messrs W. Awde, 

 J. B. Wolstenholme, and other English veterinary surgeons, I 

 have received notes of interesting cases, but in this connec- 

 tion I can only further refer to the published cases of Messrs 

 Anderson, Boddington, Cartwright, Harrison, Moir, and Wallis. 

 The French cases, by M. Cambron and by M. Yeret, are par- 

 ticularly instructive. Many of the cases give fatal results. 

 In one fatal instance a pupil of mine counted over 1200 of 

 these worms, and in a similar fatal case Mr Lewis reports that 



