Verminous disease of the intestine is often accompanied by similar disease of the stomach (gastro-intestinal strongylosis of the sheep, lumbricosis of the calf), but it also occurs apart from the presence of gastric parasites. Parasites are more frequent in the intestine than in the abomasum, because the alkaline intestinal juices prove a much more favourable medium for their development than do the acid juices of the stomach. The actual parasites may include ascarides, strongyles, hooked worms, œsophagostomes, tricocephales, sclerostomes, and various tæniæ (_Tænia expansa et alba_). Many of these have already been, or will hereafter be, referred to. Helminthiasis due to round worms like strongyles, and the various forms of hooked worm, is graver than that due to flat worms, but most extraordinarily varied collections are sometimes met with. Speaking generally, however, helminthiasis more particularly affects young animals like calves, lambs, and yearling sheep, is rarer in adults, and in all cases the complications it produces are of trifling importance in adults as compared with those caused in the young. The persistence of verminous diseases in certain infested countries, districts, farms, or pastures is explained by the enormous number of eggs or embryos passed with the fæces and disseminated with manure, as well as by the high degree of resistance of the eggs and embryos to destructive influences. =Causation.= The various forms of intestinal helminthiasis are all due to embryos or eggs of worms obtaining entrance to the stomach or bowels of susceptible animals. Nevertheless, external conditions largely favour infestation. The existence of marshes, ponds, and stagnant water on certain pastures, heavy annual rainfall, the occurrence of wet seasons, etc., favour the existence and growth of embryos, and, as a consequence, the infestation of animals. [Illustration: $1] =The symptoms= of intestinal helminthiasis are always very vague, whether the victims be oxen, sheep, or goats. They point to the slow and progressive development of a pernicious anæmia, characterised primarily by interference with appetite and digestion, then by anæmia, and finally by cachexia. The patients are dull, lose condition, suffer from depraved appetite, and, during the cachectic period, from diarrhœa, and die in a condition of exhaustion. These forms of helminthiasis are much more frequent in sheep than in oxen. =The diagnosis= is only arrived at by discovering parasites in the fæces, or, in those doubtful cases where one has been led to make a microscopic examination of the excrement, by the detection of large numbers of eggs. From an economic standpoint the =prognosis= is grave, because severely infected animals recover their condition very slowly, whatever treatment be adopted.