[ 327 1 
accounted for, if we recoiled:, that at the time when 
thefe veffels, and the ftrudure of this part, were dis- 
covered, the lymph, and every thing belonging to it, 
was utterly unknown ; and that the veffels in que- 
ftion were firft feen and confidered as performing 
another and more remarkable office : which circum- 
ffance, it ffiould feem, has prevented fucceeding au- 
thors from being duly attentive to them in the capa- 
city of lymphatics. However this be, it is certain, 
that the lymphatics of the mefentery, commonly 
called the ladeals, differ from thofe of the other 
parts in no one particular, lave that occafionally they 
carry chyle inffead of lymph or rather carry lymph 
mixed, at ftated times (that is, for two or three 
hours after the creature has taken food) with an 
emulfion of vegetable and animal fubftances, and 
coloured white by that mixture. At other times, 
(that is, during fixteen or eighteen hours out of the 
twenty-four) they contain nothing but lymph 5 and 
are, in every refped, mere lymphatic veffels, not to 
be diffinguiffied from thofe in any other part of the 
body. Their ftrudure is the fame ; the membrane 
of which they are formed, their valves, the lymph 
which they contain, the glands thro’ which they 
pafs, their diredion from fmaller tubes to larger, 
and from thefe to the blood, differ in nothing from 
what we obferve of the other lymphatics. Their 
lymph, in the mean time, is without doubt or con- 
troverfy fupplied from the cavity of the inteftines 
being the watery moifture continually exhaled there 
for the purpofes of digeftion, and for the preferva- 
tion of the alimentary canal, and as continually taken, 
up by the roots or extremities of thefe veffels, in 
