974 PROTOZOA AND OTHER ANIMALS 



of other mammals, including the tapir, rhinoceros, chimpanzee, gorilla 

 (Reichenow, 1920), and elephant (Kofoid, 1935). 



Ciliates in ruminants, except for certain species less constant in oc- 

 currence (as Buxtonella sulcata Jameson, in the caecum of cattle) are 

 localized in the rumen and reticulum. Their relative abundance in the 

 rumen and reticulum is approximately equal (Dogiel and Fedorowa, 

 1929; Wertheim, 1934a); and they are distributed throughout the con- 

 tents. Dogiel and Fedorowa found that the ciliates are somewhat more 

 abundant in the central part than at the periphery, but that the difference 

 is not very great. Distribution is sufficiently uniform so that counts of 

 a small sample from the rumen have been used for an estimate of the 

 total population. 



Poor nutrition of the ruminant can cause a rapid reduction in the 

 number of ciliates, and this may be responsible for low counts, in slaugh- 

 terhouse animals, of under 100,000 per cc. (Dogiel and Fedorowa, 

 1929), under 200,000 per cc. (Wertheim, 1934a), and under 400,000 

 per cc. (Winogradowa-Fedorowa and Winogradoff, 1929). Under 

 conditions of normal nutrition, many counts above 500,000 per cc. have 

 been obtained. Mangold (1929, 1933) stated that in sheep and goats 

 the normal number remains with much constancy at about 1,000,000 

 per cc; and Mowry and Becker ( 1930) agreed with this as regards goats. 

 Under certain conditions, the population may be much denser than this. 

 By experimental feeding Mowry and Becker obtained a count of nearly 

 7,600,000 of Entodinium and Diplodinium alone. Ferber (1928) esti- 

 mated that at 900,000 per cc. a gram of rumen contents would contain 

 about one-twentieth of a gram of ciliates. 



The total number of ciliates in an individual ruminant is enormous. 

 Calculating from a volume of material in the rumen and reticulum of 

 goats of from 2.8 to 5.2 liters, and a ciliate count of from 121,000 to 

 391,000 per cc, Winogradowa-Fedorowa and Winogradoff (1929) esti- 

 mated a population of from 471,000,000 to 1,548,000,000; for the 

 normal condition these figures should probably be multiplied by about 

 three. In an ox with from 56 to 87 liters and from 70,000 to 117,000 

 ciliates per cc, there would be nearly 10,000,000,000; and probably the 

 population may be at least five times as dense as that. 



The ciliates are consistently absent from suckling animals, but, as 

 soon as a diet of plant food begins, the faunule of the rumen and reticu- 

 lum develops. 



