Corpuscles are contained in the
blood of all Vertebrata
. In Amphioxus
they are all of one
kind, colorless and nucleated. The genus Leptocephalus
among the Teleostei
, is said to possess the same peculiarity;
but, in all other known Vertebrata
, the blood contains corpus
cles of two kinds.
, both kinds are nucleated;
but one set are colorless, and exhibit amaeboid movements,
while the others are red, and do not display contractility.
Except in the Marsipobranchii
, which have round blood - corpuscles,
the red corpuscles are oval. They attain a larger size in
the perennibranchiate Amphibia
than in any other Vertebrates.
, the blood - corpuscles are also of two kinds,
colorless and red, the colorless possessing, and the red being
devoid of nuclei. It is but very rarely that a nucleated corpuscle,
with a red color especially developed about the nucleus,
is seen in Mammalian blood; but such cases do occur;
and, from this and other circumstances, it is probable that the
Mammalian red corpuscle is a free - colored nucleus.
The colorless corpuscles of Mammalia
are spheroidal, and
exhibit amaeboid movements; the red corpuscles are flattened,
usually circular, but sometimes oval (Camelidae
) disks, devoid