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be only a variety, which is a circumftance that, as we are 
told, has occurred even in the human body. But in 
three others of this fpecies, which 1 likewife fuccefs- 
fully injected, I ftill law two dudts ; and therefore I 
am inclined to believe, that this is the conftant num- 
ber. I likewife carefully attended to the vefiel s com- 
ing from the gland on the right fide: and in the only 
two fubjedts in which the lymphatics of the neck were 
properly filled, 1 obferved, that one part of it opened 
immediately into the vein, and the other joined the 
thoracic dudf of that fide ; whilft, on the left fide, the 
vefiel which ifiiied from the gland wholly joined the 
thoracic dudf. In all the four fubjedis I evidently faw 
that the thoracic dudts open into the infide of the jugu- 
lar veins. 
This fyfiem in birds differs mod from that in qua- 
drupeds in the following pariculars. iff, In the chyle 
being tranfparent and colourlefs. 2 dly, In there be- 
ing no vifible lymphatic glands, neither in the courfe 
of the ladteals, nor in that of the lymphatics of 
th abdomen i nor near the thoracic dudts. 3 dly, In 
the feveral parts of this fyfiem in birds being more 
frequently enlarged, or varicofe, than in quadrupeds. 
In particular, this appears to be the cafe of the vefiels 
which confiitute the network at the root of the cceliac 
artery in that fubjedt from which the drawing was 
taken. The ladteals are frequently enlarged in fome 
places ; fo are the thoracic dudts ; and the lymphatics 
on each fide of the neck are commonly, when taken 
together, larger than their trunk which opens into 
the lymphatic gland. In one fubjedt, where inftead 
of two lymphatics on the left fide I found only one, 
that vefiel was as large as a crow- quill j whilfi the 
lower 
