SOLTDUNGULA 375 



Knox as " Animals similar to Trichina; 9 ' by Diesing as the 

 " Nematoideum equi caballi ;" by Mr. Littler as " Extremely 

 small ascarides," in a letter to Mr Yarnell ; by Mr Varnell 

 himself as " Entozoa in various stages of growth " and by 

 Prof. Williams as " Entozoa from the intestinal walls/ ' in a 

 letter to myself, dated March 13th, 1873. In reference, 

 however, to Mr VarnelFs account of Mr Littler' s specimens I 

 may observe that the appearances which he at first merely 

 described as " blood spots/' he afterwards characterised as 

 dark points "containing young worms in various stages of 

 growth." 



As regards the course of development of this worm we have 

 yet much to learn. Although the worm is a frequent cause of 

 epizooty in this country it appears to be but little known on 

 the Continent. Krabbe makes no mention of the helminthiasis 

 set up by the four-spined strongyle, but he points out that the 

 young occupy the mucous membrane, in which situation they 

 lie coiled so as to present to the naked eye the appearance of 

 little dark spots (Husdyrenes Indvoldsorme, 1872, p. 17, ' Aftryk. 

 af Tidsskr. for Vet/). However, Leuckart's account of the 

 appearances presented in a case brought under his notice is 

 instructive. He writes : " I have hitherto had only a single 

 opportunity of examining the strongyle capsules in the intestinal 

 membrane of the horse. Their presence is limited to the caecum 

 and colon, but they are so abundant in this situation that their 

 numbers may be estimated by many hundreds. It was thus 

 likewise in the case in question, the investigation of which by 

 myself was rendered possible through the friendliness of Prof. 

 Haubner of Dresden. The capsules were of oval form, and 

 glimmered through the mucous membrane as opaque spota, 

 mostly from one to three millimetres in size. In several of 

 these capsules nothing was found beyond a greasy mass of a 

 brownish color, which might readily be taken for a tuberculous 

 substance ; but the greater number of them contained a coiled 

 worm, from three to six millimetres long, their breadth being 

 0-15 to 0-26 mm. (which is ^' to "). They exhibited a highly 

 colored stout intestine, and a thick-walled oral capsule of 

 0'022 mm. in depth and 0*025 mm. in breadth. On the dorsal side 

 two three-cornered chitinous lamellae arise from the shallow 

 floor of the small oral capsule. The cuticle, notwithstanding 

 its firm structure, was still destitute of annulations. The tail 

 (0'15 to 0*18 mm. in length) was strongly marked off from the 



