It is produced by the _Strongylus convolutus rel Ostertagi_, which becomes embedded under the epithelium of the mucous membrane and causes the formation of small nodules, the size of a pin’s head or lentil, which can be detected on palpation. The cavity thus formed beneath the epithelium communicates with the gastric cavity by a little orifice, through which the cephalic end of the parasite passes. PARASITIC GASTRO-ENTERITIS, DIARRHŒA, AND ANÆMIA IN CATTLE, SHEEP AND LAMBS. A disease characterised by anæmia with wasting and diarrhœa is sometimes produced in cattle by the presence in the fourth stomach of small strongyles varying in size between 3 and 9 millimètres in length, according to the variety encountered. One variety of the smaller size has been named by McFadyean _Strongylus gracilis_. Penberthy, who described the disease in the _Jour. of Comp. Path. and Therap._ for 1894, p. 249, states that in certain cases he also found the _Strongylus ventricosus_, the _Tricocephalus affiinis_, and minute straight worms about ²⁄₂₅ of an inch long, which he regarded as anguillulæ. Neumann declares that pernicious anæmia with catarrh of the abomasum in young animals is due to _Strongylus convolutus_. =The symptoms= comprise anæmia, wasting, and diarrhœa of varying severity. In acute cases, which are common between the ages of six months and two years, husk is sometimes (accidentally) present. The disease is rarest in summer. Certain animals lose flesh rapidly, though appetite is retained. Acute fœtid watery diarrhœa follows. The animal shows tenesmus, appears dejected, and has a temperature of 103° to 105° Fahr. The mucous membranes become pale, the pulse small and weak, the appetite capricious, the eyes sunken, belly tucked up, coat harsh and dry and hide tight. Wasting is rapid. The animals are listless, and often lie down for long periods. Death occurs from exhaustion. =The parasite.= Scrapings from the abomasum and intestine when diluted with water and viewed under a lens show minute bodies resembling short, fine hairs. When isolated these are easily visible with the naked eye. _In situ_ they appear to be lying on the mucous membrane, sometimes with the head fixed in the latter. They vary in length from ³⁄₂₅ to ⁶⁄₂₅ of an inch, and are brownish in colour. For a detailed description see Penberthy _loc. cit._ McFadyean (_Jour. of Comp. Path. and Therap._ for 1896, p. 314) also gives a very full description, illustrated by plates, of the two species of strongyles which he regards as the cause of gastritis in cattle in England. [Illustration: $1]