[ 222 ] 
lower part of it, which entered the gland, was much 
fmaller. 
Th us far the account of what I faw : I fhall next 
beg leave to obierve, that, as the fuppofed want of 
this fyllem in birds has been conlidered as a ftrong 
argument in favour of abforption by the common veins, 
now, fince we find it not wanting, that theory 
muft be much weakened. And I may likewife add, 
that abforption feems to be carried on in birds, as in 
quadrupeds, by this fyftem, at leaft principally ; in- 
deed I am inclined to believe, entirely ; for no argu- 
ments brought in favour of abforption by the com- 
mon veins appear to me of equal validity with thole 
that can be urged againlf it. The contrary opinion 
is indeed embraced by the mod: learned and acute 
phyfiolog'rft of the prefent age, who, treating of this 
lubjedt, exprefles himlelf in the following manner : 
“ It is a ftrong argument in favour of ablorption by 
“ the common veins, that neither birds, amphibious 
“ animals, nor fill with cold blood, have either the 
“ ladtealorthe lymphatic fyftem. Nature common- 
“ ly oblerves a pretty ftridt analogy in her works, and 
“ makes ufe of fimilar organs to perform fimilar func- 
“ tions. Now in all animals, quadrupeds and the 
« whale excepted, we mult admit of abforption by 
« the mefenteric veins, if in thofe animals there is 
“ no other way for the chyle to get into the blood. 
“ And if thofe veins in birds and amphibious animals 
“ abforb the chyle, it is very probable they likewife 
« abforb it in quadrupeds, in which they equally 
<c exift.” But the exigence of this fyftem in birds 
is not the only fadt which might be adduced to inva- 
lidate the above opinion j for I have feen a part of it 
very diftindtly in one of the a?nphibia t viz. the 
Turtle 
