and Circulation of the Blood . 131 
After many Obfervations made by Mr. 
Leeuwenhoek on the Blood of Cocks, Spar¬ 
rows, Frogs, Fronts, Perch, Cod, Salmon, &c u 
he affirms, that the red Particles in the 
Blood of Birds, Fifes, and Water-Animals, 
are conflantly * flat and of an oval Figure; 
that is, they are longer than their Breadth, 
and appear as in Plate X, Fig. V, The fe- 
rous Part of the Blood in Fijhes and Aquatic 
Animals is alfo greatly more, in Proportion 
to the red Particles, than it is in Beafts or 
Men , and the Particles themfelves are larger: 
fo that, by being bigger, and fwimming far-* 
ther afunder, they may be feen much better. 
Mr. Leeuwenhoek obferved the Blood 
circulating in the filmy Wings of a Bat ■f*, 
and likewife in its Ears, and found the Glo¬ 
bules thereof perfectly round : wherefore, 
allowing his Affiertion, that in Fifhes and 
Birds they are always flat and oval, we need 
no longer hefitate how to clafs this odd 
Creature; but, notwithflanding its flying, 
fhall pronounce it to be a Beajl . 
He tells us, that Bats can fee as well by 
Day as Night: but he fuppofes the Heat 
and Drynefs of the Day-Air would fhrivel 
up the thin Membranes of their Wings, and 
confequently flop the Circulations there; 
# Arc. Nat. Tara.. I. Part II. p. ri. Again, Tom. IL 
jEpift. 128. Again, Tom. IV. Epift. 65, 
+ Arc. Nat . Tom. IV. Epift. 67. 
whereas 
