[4] Lühe, M., “Ueber d. Fix. d. Helm. a. d. Darmwand ihrer Wirthe u. die dadurch verursachten path-anat. Veränderungen d. Wirthsdarmes,” _Trans. of IVth Intern. Zool. Cong._, Berlin, 1901; Mingazzini, P., “Ric. sul var. modo di fiss. delle tenie alla par. int. e sul loro assorbimento,” _Ric. Lab. Anat. Roma e altri Lab. biol._, vol. x, 1904; Shipley, A. E., and E. G. Fearnsides, “The Effects of Metazoan Parasites on their Hosts,” _Journ. Econ. Biol._, 1906, i, 2. Generally, the disorders caused by loss of chyle are insignificant when compared with those induced by the GROWTH and agglomeration of the helminthes. The latter may cause chiefly obstructions of small vessels or symptoms of pressure in affected or contiguous organs, with all those complications which may arise secondarily, or they may even lead to the complete obliteration of the organ invaded. Of course the symptoms will vary according to the nature of the organ attacked. In consequence also of the MOVEMENTS of the parasites, disorders are set up that may tend to serious pathological changes of the affected organs. The collective migrations, undertaken chiefly by the embryos of certain parasites (as in trichinosis, acute cestode tuberculosis), are still more harmful, as are also the unusual migrations of other parasites, which, incidentally, may lead to the formation of so-called worm abscesses or to abnormal communications (fistulæ) between organs that are contiguous but possess no direct connection. Recently, several authors have called attention to the fact that the helminthes produce substances that are TOXIC to their host; and the effects of such poisons explain the pathology of helminthiasis far more satisfactorily than the theory of reflex action. In a number of cases these toxic materials (leucomaines) have been isolated and their effects on living organisms demonstrated by actual experiments. It also appears that the absorption of materials formed by the decomposition of dead helminthes may likewise cause toxic effects. However, our knowledge of these conditions is as yet in its initial stage.[5] [5] Moursson et Schlagdenhauffen, “Nouv. rech. clin. et phys. sur quelq. liquides organ.,” _C. R. Acad. Sci._, Paris, 1882, p. 791; Debove, “De l’intox. hydat.,” _Bull. et Mém. Soc. méd. des Hôpit._, 1888; Linstow, v., “Ueb. d. Giftgehalt d. helm.,”_Internat. Monatsschr. f. Anat. u. Phys._, xiii, 1896; Peiper, “Z. Symptomatol. der thier. Paras.,” _Deutsche med. Wochenschr._, 1897, No. 40; Mingazzini, P., “Ric. sul veleno d. elm. int.,” _Rass. intern. d. med. modern. Ann._, 1901, ii, No. 6; Vaullegeard, A., “Etud. exp. et crit. sur l’action d. helm.,” _Bull. Soc. Linn. de Normandie_, 1901, 5, Ser. T, vii, p. 84, and others.