Of Vegetation. 341 
mg the mixture according to the many 
different purpofes (he defigns it for 5 either 
for long or more lax fibres of very different 
degrees in animals, or whether it be for the 
forming of woody or more foft fibres of 
various kinds in vegetables. 
The great variety of which different fub- 
ftances in the fame vegetable prove, that 
there are appropriated veffels for conveying 
very different forts of nutriment. And in 
many vegetables fome of thofe appropriate 
veffels are plainly to be feen replete either 
with milky, yellow, or red nutriment. 
Dr. Kei//j in his account of animal fecre- 
tion, page 49, obferves, that where nature 
intends to feparate a vifeid matter from 
the blood, (he contrives very much to retard 
its motion, whereby the inteftine motion of 
the blood being allayed, its particles can the 
better coalefce in order to form the vifeid 
fecretion. And Dr, Grewy before him, ob- 
ferved an inftance of the fame contrivance 
in vegetables where a fecretion is intended, 
that is to compofe a hard fubftance, viz. in 
the kernell or feed of hard ftone fruits, 
which docs not immediately adhere to, and 
grow from the upper part of the flone, 
Z 3 which 
