848 
a, Haversian canal; b, concentric lamine ; c, lamine of connection ; 
d, corpuscles, with their system of tubes. : 
The parts marked a, b, and d constitute an Haversian system. 
figure includes three systems with lamine of connection uniting them, 
lected, it will be found to contain no Haversian 
canals or corpuscles, but to be extremely thin 
and transparent. Such a portion, when viewed 
with the one-eighth of an inch object-glass of 
Mr. Powell’s microscope, will present a deli- 
cate granular aspect with the surface nodulated. 
This granular appearance arises from the sub- 
stance of the bone being composed of minute 
irregularly spherical granules. It is not diffi- 
cult to trace this structure in any specimen of 
bone, though in some it is much more distinct 
than in others. Specimens put up in Canada 
balsam do not show the minute structure very 
well. It. is best to pies the object between 
two slips of glass with a little plain water. 
A delicate spicula from the point where os- 
sification is going on is usually very good for 
illustrating the granular tissue. 
But the granules may be obtained separated 
from each other, so that each individual may be 
eXamined apart from its fellows. When so 
eee to view, they exhibit a tolerably re- 
gular character, being mostly spherical, some 
few having an oval form. In some specimens 
the oval predominates over the spherical con- 
formations. Often a few will be found which 
are egg-shaped, with the smaller end elongated, 
(see fig. 449,) though to no great extent. The 
osseous granules may be gained by subjecting 
bone to high-pressure steam, or to a red heat, 
till all the animal matter is removed. In either 
instance the granules may be obtained by taking 
OSSEOUS TISSUE. 
Fig. 448. 
Transverse section from the dense portion of the femur. 
The 
Ultimate osseous granules obtained by depriv 
bone of its animal matter. 
a small portion of the so treated bone, & 
ting it with water, and then gently redu 
to a powder between the slips of glass 
manipulation the granules individually ¥ 
rendered evident when the specimen 
mined under ahigh power. But, by t 
ing down of the mass, man ules are 
sarily broken ; to remedy this imperfect ai 
