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Blood, U W the fmall Artery, wberein the Blood <lid ' 
retain its full Gourfe, although it was fo near to the 
Vein as T U, whereout the Blood did flow, and was 
extravafated. This feemed to me very ftrange in the 
beginning, but when I obferved that the Blood-veffel 
U W was united at W, to a large Blood-veffel that did 
carry the Blood to the Heart, which we call a Vein, 
then this Blood out of U W, was carried on with fo 
great a fwiftnefs, and as it was fuckt in , juft as if it 
v/as impelled from T to U 3 nay, even after fuch a 
manner, that I did imagine, that if the Vein at II was 
not united withT,but had only lain with its opening at 
U, in the extraVafated Blood, that fothe extra vafatcd 
Blood was only for a little while fuckt up and carried 
along. 
Then I faw a Vein, wherein the running of the 
Blood feemed very ftrange to me 3 for example: Let 
Fig. 4. a b be an Artery wherein the Blood is impelled 
with great fwiftnefs from a to b, then we muft call b 
c, whereby the Blood is carried down, or towards the 
Heart a Vein : but what name muft we give to b e, 
being thatclofe by it there did lye another AvtQry^viz,. 
^ c e, in which laft Veffel the Blood was alfo carried 
from the heart, from D to C. Now if the Vein b c 
be united with the Artery d e, as is feen .at C, and 
thus the Blood is carried from c to e 5 to be ihort, we 
ought juftly to call b c, a Vein, and the Blood coming 
to C, and being there infufed in c e, is the arterial 
Blood, bccaufe it is carried there from th^ .|ieart, it 
heing certain that d c e is an Artery. 
Amongft the reft, I have had a Tadpole before my 
fight, wherein I could not at all perceive any motion 
of the Blood, how attentively foever I did look on it, 
whereof at firft no reafon did appear to me, or what 
(hould be the occafion of this ftagnation of the Bloody 
yetwiien I came to contemplate this Animal with the 
naken 
