DOMESTIC RUMINANTS AND THE HORSE 57 



reaching the infected parts of the ahmentary canal with a rubber 

 tube for the purpose of obtaining samples of the contents. One 

 often finds many species of the protozoa of the horse in liquid 

 pressed from the fresh feces, but this could probably not be used 

 as a reliable index of the presence or absence of protozoa in the 

 cecum or colon, though this point should be carefully ascertained. 



Among the more important problems are these: (i) Do the in- 

 fusoria of the horse assist in cellulose digestion? (2) Do they 

 assist in synthesis of proteins from the amides present in the hay 

 and grasses eaten by the horse? (3) Do they serve the horse by 

 keeping down excessive growth of various fungi? (4) Are they 

 pathogenic to the horse? (Fantham, 1921, indicates that Cyclo- 

 posthium may be so.) (5) How is the infection spread from horse 

 to horse? The infusoria may be present in the feces, as stated 

 above. But, in the absence of cysts, how can these trophozoites pass 

 safely through the stomach to reach the large intestine ? 



Hsiung (1929) has described the tentacled stage of three species 

 of sucTORiA found in horses. Neither he nor anyone else has seen 

 the ciliated stages of these forms. From what we know of free- 

 Hving SUCTORIA, we might expect the occurrence of such stages. 

 Search should be made for them. They should be quite small. 



The ciliates of ruminants and the horse ofifer unparalleled oppor- 

 tunities for cell problems. Sharp's (1914) masterpiece on the 

 neuromotor apparatus of Diplodinium will long be remembered. 

 One of the authors (Becker) has stained the neuromotor ap- 

 paratus in sections of the ciliate which appears in Becker and 

 Talbott (1927) as Diplodmium bursa. It seems to be quite similar 

 to that of D. ecaudatum except that the lines are finer, although the 

 ciliate is larger. The apparatus should be worked out in Cyclo- 

 posthium, Entodinium, Ophryoscolex and others. Sharp gives sev- 

 eral methods of staining it. Yabroff's (1928) modified DeFano 

 technique should also be tried. 



Giardia equi found by Fantham (1921) in the colon of the 

 horse should be restudied according to Hegner's biometric method. 

 Like G. hovis, it has never been figured. It has not been found here 

 in twenty-six horses examined. 



In this chapter we have pointed out problems which should 

 readily lend themselves to solution, except in one case, where 

 we have stated the difficulty. Both of us are already working on 

 some of them ; but, when we contemplate the vastness of the 



