WORMS. 211 



further forward, on the ventral surface. Among the 

 Nematodes are included a number of relatively small 

 species, living free in the earth, and sucking plant- 

 parts, while other forms fairly closely related live 

 parasitically in plants, and often cause very serious 

 plant diseases {e.g. Beet Eelworm) ; a larger number of 

 species are parasitic in animals. The free forms and 

 those parasitic in plants lay relatively few, but very 

 large, eggs, although, in several species, increase is 

 furthered by a succession of many generations in the 

 year. The Nematodes parasitic in animals lay very 

 numerous eggs, even several millions. Harmful 

 species are known from the following families: 

 1. Palisade Worms (Strongylidce), 2. Whip Worms 

 (Trichotrachelidce), 3. Slender Thread Worms {Fi- 

 laridas), 4. the Round Worms (Ascaridce), 5. Eelworms 

 {AnguillulidoB) . 



I will successively treat of the harmful forms, but 

 since many species belonging to different families 

 infest the digestive organs of the different domesticated 

 animals, causing similar symptoms of disease which 

 may be dealt with in much the same way, the 

 following general sketch is first given : — 



Nematodes in the Gut (more in young animals than 

 old) cause the following symptoms: (1) Appetite 

 variable. (2) Nutrition in general affected, even if 

 sufficient food is taken; constipation or diarrhoea; 

 belly much drawn in or else, and usually, swollen 

 out. The animal itself is thin, and has (except horse) 

 a tendency to vomit. (3) An itching aU over the 

 body, especially at the nostrils and anus. The 

 animal rubs and bites the sides of its body. (4) 

 Tongue covered with a thick, soft, yellowish coating. 

 A sweet smell from the mouth. (5) The skin is 

 tense, lacking its usual elasticity. (6) The animal 

 suffers from spasmodic colic, and (7) disturbances of 

 the nervous system (whining or crying ; unrestrained 

 or suppressed fits). Remedies: Horses and cows 



