ment of disease symptoms. It not infrequently happens that 

 animals fed on a " natural ' ' diet may be receiving insufficient 

 phosphates or calcium or other elements, and the use of licks 

 containing these substances immediately increases the general 

 condition of the animal and so assists in control of parasitic 

 diseases. 



(b) Diet — It is extremely difficult to separate many para- 

 sitic diseases from those caused by deficiencies in diet. There 

 is evidence to suggest that in many cases the two are so closely 

 interwoven as to be inseparable and that their effects are mu- 

 tually cumulative. There is no doubt that in very many cases, 

 a sufficient, well balanced diet, balanced in all its accessory 

 factors as well as its main constituents, will prevent parasitic 

 disease and will often actually reduce the numbers of para- 

 sites harboured. Pasture treatment, such as "top-dressing," 

 is often a valuable way of doing this. This adequate diet is 

 jiarticularly important for immature animals and every effort 

 should be made to secure this. This is, of course, true for all 

 preventive measures to be taken but is especially important, ia 

 connection with diet. 



Bibliography 



AcKERT, J. E. 1939. — Factors in the resistance of chiekeus to 

 parasitic worms. Proc. 7th World's Poultry Cong. & 

 Expo., Cleveland, pp. 265-276. 



Cameron, T. W. M. 1933. — The bursate lungworms of domesti- 

 cated animals. Imp. Bur. Agrie. Parasit., 36 pp. 



1934. — The internal parasites of domestic animals, 

 xii + 292 pp., London. 



H.\LL, M. C. 1917. — Manure disposal as a factor in the control 

 of parasitic diseases of live stock. J. Am. Vet. Med. As- 

 soc, n. s., V. 4: 67r)-67.S. 



1936. — The control of animal parasites. 162 pp., 

 Evanston, Illinois. 



1938. — Three parasites which habitually surmount onr 

 sanitary barriers. Livro Jub. Travassos, Rio de Janeiro, 

 pp. 195-211. 



MONNIG, H. O. 1938a. — Veterinary helminthology and ento 

 mology. 2nd ed. xv + 409 pp. London. 



1938b. — Pasture hygiene with respect to parasitic dis- 

 eases. 13th Internatl. "Vet. Cong., v. 1 : 666-671. 



Parnell, I. W. 1934. — Studies on the bionomics and control of 

 the bursate nematodes of horses and sheep. Pt. I. Canad. 

 J. Res., Sect. D, v. 10: 532-.^38. 1936a.— Idem. Pt. IL 

 Ibid, v. 14: 71-81. 1936b.— Idem. Pt. III. Ibid., v. 14: 

 172180. 1937.— Idem. Pt. IV. Ibid., v. 15: 12714.^ 1938. 

 —Idem. Pt. V. Ibid., v. 16: 73-88. 1939a.— Idem. Pt. VI. 

 Ibid., V. 17: 68-86. 1939b.— Idem. Pt. VII. Ibid., v. 17: 

 187-204. 1940.— Idem. Pt. A'lII. Ibid., v. 18: 371-394. 



1935. — On the. control of the free-living larvae of 

 bursate nematodes of domestic animals. Trop. Agric, v. 

 12: 109-113. 



1936. — Notes on the survival of the eggs and free- 

 living larvae of sclerostomes on pasture. Sc. Agric, v. 16: 

 391-397. 



1939. — Some notes on the chemical control of the free- 



living stages of bursate nematodes. Canad. J. Comp. Med., 

 V. 3: 84-87. 



Rappenspercer, H. B. 1927. — The swine sanitation system as 

 developed by the Bureau of Animal Industry in McLean 

 County, 111. U. S. Dept. Agric. Tech. Bull. No. 44, 20 pp. 



R.\ILLIET, A. 1918. — Oxvurosis in the horse. Vet. Rev., v. 2: 

 139157. 



Ransom, B. H. and Hall, M. C. 1920. — Parasitic diseases in 

 their relation to the live-stock industry of the southern 

 United States. J. Am. Vet. Med. Assoc, n. s., v. 10 : 

 394-413. 



Ransom, B. H. [1927 J. ^The prevention of roundworms in 

 pigs. XT. S. Dept. Agric. Leaflet No. .">, 8 pp. 



Ross, I. Clunies and Gordon, H. McL. 1936. — The interna 

 parasites and parasitic disease of sheep, xx + 238 pp. 

 Sydney, Australia. 



Ross, I. Clttnies, Chamberlin, W. E. and Turner, H. N. 

 1937. — The influence of improvement of pastures and rota- 

 tional grazing on parasitism, body weight and fleece pro- 

 duction in crossbred sheep in Tasmania. J. Council Sc. & 

 Indus. Res., v. 10: 313-326. 



Schwartz, B. 1928. — Gastrointestinal parasites of equines 

 and control measures. J. Am. Vet. Med. Assoc, n. s., v. 

 26: 855-870. 



1934. — Controlling kidney worms in swine in the south- 

 ern states. U. S. Dept. Agric. Leaflet No. 108, 6 pp. 



Swales, W. E. 1927. — The practitioner's role in parasitology. 

 Canad. J. Comp. Med., v. 1: 17-21. 



1940a. — The helminth parasites and parasitic diseases 

 of sheep. Pt. 1. Canad. J. Res., Sect. D, v. 18: 29-48. 



1940b.— Idem. Pt. II. Canad. J. Comp. Med., v. 4: 

 1.55161. 



1940c. — The use of phenothiazine in veterinary para- 

 sitology. Ibid., V. 4: 333-341. 



Swales, W. E. and From.\n, D. K. 1939. — An apparatus for 

 measuring the ' ' flash ' ' thermal death point of micro- 

 scopic animal organisms and its use with ova of Ancaris 

 Uimbricoides. Canad. J. Res., Sect. D, v. 17: 169-177. 



Taylor, E. L. 1931. — The faeces in worm diseases: their value 

 for diagnosis, and their hygenic disposal on the farm. Vet. 

 Rec, V. 18(24): 639-644. 



1933. — The control of red-worms in horses. Ibid., n. 

 s., V. 13(18): 399-506. 



1935. — The veterinarv aspect of parasitologv. Ibid., 

 V. 15(5): 103-114. 



1938a. — Grazing hygiene with respect to parasitic dis 

 eases. Proc 13th Internatl. Vet. Cong., v. 1 : 672-682. 



1938b. — Observations on the bionomics of strongyloid 

 larvae in pastures. I. The duration of infection in pasture 

 herbage Vet. Rec. v. .50(40): 1265-1272. 



1939. — The role of pastures in the development of the 

 strongyloid diseases of grazing animals. Ibid., v. 51(1S): 

 495-504. 



308 



