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time of mentioning that I firft faw thofe veffels, as 
near as I can recolledt, in September or Odober 
1763, which, as far as I know, was before they had 
been feen by either of them. 
But although it was an eafy matter to fee thofe vef- 
fels in the turtle, yet it was far from being fo in birds 
and filh ; as the gentlemen of the Society will readily 
believe, from their having been fo often fought for in 
vain by fo many eminent anatomilfs, particularly of 
this age. I may add, that the difcovery in birds did 
not give me fo much trouble as that in Mi, though 
now, fince I have feen them in the latter, I can more 
readily find them there than in birds or quadrupeds. 
After feeing them in birds, 'and in one of the amphi- 
bia, I was very defirous of determining whether fifli 
were, or were not provided with thofe veffels. This I 
endeavoured to do in the fame way that I had found 
them in birds, that is, by tying up the mefenteiies cf 
live-fifhj and for this purpofe I went frequently to 
the markets, and examined feveral fmall ones. I 
likewife differed fome larger, when dead, but in 
vain. I next went to Brighthelmflone, where I found 
kingfton, or monk-filh, a fpecies of fl;ate. Thefe 
being very large, and having a lean mefentery, feemed 
well fitted to my purpofe. I opened two of them 
alive, tied up their mefenteric veffels, and put thetii 
again into the fait water 5 and though one of them 
lived an hour, I could not obferve any lacfleals 
either upon its intefline or its mefentery. After this, 
I repeatedly examined the inteftines and mefenteries 
of common fkate and cod, and at lafl was fo fortu- 
nate as to difcover the ladteals, and get a pipe into 
one of thofe veffels on tlie mefenteries of each of 
thefe 
