RUMINATION. ] 37 



9. Three animal substances of undetermined nature. 



10. And lastly, chlorides, carbonates, phosphates, and 

 sulphates of soda and potash, besides carbonate and phos- 

 phate of lime. These different salts varied according as to 

 whether the animals received straw, hay, or oats. 



Gruby and Delafond have shown that myriads of infusoria 

 develop in the rumen. Their development appears due to 

 the germinating powers of heat and moisture, which seem to 

 be the chief causes of the disintegration and partial solution 

 of alimentary matters ; changes which appear, as Colin says, 

 totally distinct from any true digestion, such as that occur- 

 ring under the influence of the acid secretions of the true 

 stomach. 



In the reticulum, food undergoes changes precisely similar 

 to those observed in the rumen; and indeed the second 

 stomach might almost be regarded as an extension or pouch 

 of the first. Its special function appears to be retaining 

 fluids swallowed and fluids passing into it from the rumen, 

 its contents being always very liquid. The fluids within it 

 are remarkable for a greater alkalinity than those of the 

 paunch. Peyer believed the food underwent a process of 

 crushing in the honeycomb bag, but this is not the case. 



Referring to the passage of the contents of the two first 

 stomachs back to the mouth, I may mention that the forcing 

 action attributed to the whole, or only to the anterior part 

 of the rumen, or, again, to the reticulum by some, is all 

 imaginary. Colin has shown, by a very interesting experi- 

 ment, that the gradual insinuation of food between the pil- 

 lars of the gullet is sufficient for the regurgitation essential in 

 the act of ruminating. He introduced three metallic sutures 

 through the lips of the canal, as represented by Fig. 71. 



The animal was fed, and afterwards ruminated as usual, 

 indicating no disturbance or perceptible difference in the 



