Of Birds. 41 
needs make a fhallower Arch, and fo force the infides of the 
Grinders clofer together. And as the MiUftones are peck'd 
and cut with fmall Gutters,leaft their force (hould be evaded: 
fo the Griftly Lining of the Gizard is all over rough, and 
gather d into anfwerable Furrows. And becaufe the force- 
able motion of the Grinders, muft needs work the Meat 
from under them : as .therefore in fome Mills there is one 
attends mil to turn the Grift under the Stone 3 fo the Re- 
dutlor here, to deliver it back to the Grinders, and fo over 
and over, till it be fufficiently elaborated for the Guts. 
And as the ftrong and continual motion of all thefe Muf- 
ades,is taught us from their ftrucl:ure,fo likewife from their 
red colour, which efpecially in the Grinders is intenfe. 
Hence in a Fifb, the Mufades which move the Fins are ufu- 
ally Red, although the reft of the Fleih is very white : And 
fo the Leg of a Domefticl^ Fowl. Whereas the Wings alfo 
of a Wild Fowl, are of the fame colour. So likewife the 
Flelh of a driven Calf, or of a Hare, though that of a Coney 
be white. And that which comes nearer, the Heart in all 
Creatures, having the like continual motion, is of a Red 
Colour. 
The Guts are of different length and bignefs, not always 
proportionable to that of the Bird, but the nature of the 
Meat. So thofe of a Cafowary, though it be neceflary, that 
they fhould contain Meat enough for fo great a Body : yet 
not, that the Meat, which is very nutritive,fhould make any 
long voyage. Yet is it needful there (hould be a Connivent 
Valve before the Rectum, for the guarding of fo open a paf- 
fage. And fo with Variety in other Birds, according as they 
feed on Worms, Seeds, Fruits, Flys, or Shell d Infecls, requiring 
a longer, or more open paffage, for their more deliberate, 
or fafer Tranfmiffion to the Anus.* 
The Indentures alfo feem to be made, and with variety, 
to the fame Intent : fc. That the Guts hereby receiving the 
greater Contraction and Dilatation,may fo much the more 
forceably detrude the Meat, or more eafily give way to it 5 
as it isfofter, or mixed with Shells, Stones and the like. 
The £>fd,efpecially where large, and made for a further 
Concoction of the Meat 3 for the better Retention hereof, 
where they open into the Reclum, are very ftraight. And for 
the fame reafon, alfo thinner and lefs Mufcular than the 
F other 
