Page:Midland naturalist (IA midlandnaturalis01lond).pdf/369

Synouymy.—Strongylus gigas, Rudolphi; Ascaris renalis, Gmelin; Lumbricus increnibus, Blasius; Fusaria, Zeder,

Larve.—The embryos are vermiform, and measure about the ⁠1/165⁠ of an inch in length. In their higher larval state they have been recognised as filarise (F. cystica.)

Intermediate Host.—From the anatomical observations of Schneider and Leuckart, it would seem that the immature worms dwell chiefly in freshwater fishes. Thus, the so-called Filaria cystica must be regarded as an immature Eustrongylus gigas. Hitherto, this little worm has been found occupying cysts or capsules, situated immediately beneath the peritoneal membrane in Galaxias scriba, and in certain oceanic fishes belonging to the genus Synbranchus. According to the eminent piscicologist, Müller, the Galariidæ present strong affinities to the Salmonidæ, but Cuvier considered them as essentially modified pikes (Esocidæ.)

Experiments—Balbiani attempted to rear Eustrongyli by direct experiment. He administered the ova to dog, but obtained only negative results. Similarly, his experiments on reptiles and fishes failed.

Remarks.—It the conclusions of Schneider and Leuckart be correct—and these make it appear that we must hold certain freshwater fishes as responsible media of infection—one can only express surprise that man is so seldom victimised by this parasite. The Syanranchi, being tropical fishes, can have little part in the infection of animals apart from seals. One must suppose that pumas, dogs, wolves, gluttons, raccoons, minks, weasels, and other carnivora contract this worm by attacking, capturing, and devouring fishes at times when they are prevented from obtaining other and more readily accessible kinds of food. How this parasite should in some instances gain access to herbivorous animals is not so clear.

Lit.—All standard works, and especially Leuckart's. One of the most remarkable memoirs quoted by Davaine is that of Clamorgan. In this old writers work, "La Chasse de Loup," dated 1583, the kidney-worms, or Eustroagyll of modern writers, are characterised as "serpents and highly venomous beasts."

Syn.—Strongylas longexaginatus, Diesing; Filaria bronchialis, Rudolphi; Hamularia, Trentler.

Larvæ.—Unknown.

Remarks. This small viviparous entozoon, hitherto only twice encountered in the human body, is doubtless identical with Strongylus longevaginatus. The original specimen was discovered by Trentler in Germany, in 1791; the second being found by Dr. Jortsits, in Transylvania, many years afterwards (1845,) The males measure half an inch and the females rather more than an inch in length.

Syn,—Dochnius anchylostomum, Molin; Anchylostama duodenale, Dubini; Strongylus quadridentatus, Von Siebold; Sclerostonus, Cobbold.