Of Quadrupeds. 
quatcd parts thereof into the Gut. In this motion, the ut- 
rnoft Mufcular Fibers contract the Stomach in length $ and 
the inermoft, in breadth. 
Aftrittion, is a Contraction only about the Pylorus-, per- 
formed by the inermoft Fibers alone. For the firmer Re- 
tention of the Aliment, and its orderly difmiffion into the 
Gut. 
Vndulation, is when the Contraction is made in feveral 
parts of the Stomach fucceffively, beginning at one Orifice, 
or End, and terminating at the oppofite. Made alfo by 
the Inner Fibers 5 after the fame manner, as the Vndulation 
or Periftaltick Motion of the Guts. The ufe of it, is either 
for Excretion or Eructation. If it begins from the Quiet, it 
ferves, after the fined of the Aliment is difcharg'd by Corru- 
gation^ for Excretion of the reft. But if the Vndulation be 
Inverted,or begins from the Pylorus,k produceth Eruflation. 
Anfwering to the like Inverted Motion, which fometimes 
happens in the Guts. 
Convulfion, is a forcible and fuddain Contraction of all 
the Orders of Fibers, outer, middle, and inmoft. The ufe 
hereof with Vndulation, is for Vomition. For firft, there is 
only an Inverted Vndulation, that is, I conceive, when there 
is only a Naucea or tendency to Vomit. Which Vndidation 
alfo, carries part of the matter by degrees, to the upper 
mouth of the Stomach. And growing quicker and ftronger, 
at laft turns into a Convulfion $ the Stomach being hereby 
contracted both in width and length,and the Pylorus forced 
up to the upper Orifice (as a Bar bars Puff in powdering the 
Hair, or the Bladder in the Injection of a Clyfter) and fo 
produceth actual Vomition. 
The Voluntary Motion of the Stomach, is that only which 
accompanies Rumination. That it is truly voluntary, is 
clear, from the Command that Ruminating Animals have 
of that Action. For this purpofe it is, that the Mufcu/es 
of their Venters are fo thick and ftrong 3 and have feveral 
Duplicatures as the Bafes of thofe Mufcules^ whereupon the 
ftrefs of their motion lies. By means whereof, they are able 
with eafe to -rowl and tumble any part of the meat from 
one Cell of the fame Venter to another, or from one Ven- 
ter to another, or from thence into the Gulet, whenfoever 
they are minded to do it. So that the Ejection of the meat 
D in 
