KOLLIKER, ON MUSCULAR FIBRE. 31 
at the same time, is the doctrine of the identity of cartilage 
with bone and connective tissue, deprived of one of its most 
important supports. 
K6.i1KeR on the Structure of Muscutar Fisre 
(‘Zeitsch. f. Wiss. Zool.,’ vol. viii, p. 311.) 
KOLuikeEr states in his recent examination of muscle, made 
with reference to certain observations by Leydig on the same 
subject, he has found that in recent muscular fibre, besides 
the contractile parts and the nuc/ez, an interstitial substance 
exists presenting peculiar morphological characters, and 
which would appear, in all probability, to play an important 
part in the physiological and pathological processes in muscle. 
If a portion of recent frog’s muscle be examined carefully, 
and with good glasses, in an indifferent medium, two con- 
stituents in the muscular fibre will be perceived : 
1. The contractile, transversely or longitudinally striped 
substance, and— 
2. Very pale rounded corpuscles imbedded in the con- 
tractile substance, and disposed in long linear tracts. These 
granular tracts exist throughout the entire thickness of the 
fibre, on the surface as well as more deeply, and are so nu- 
merous as apparently to constitute no inconsiderable element 
of the muscular fibre. They are most readily seen in the 
longitudinally striped fibres ; but even in these it is not easy 
to determine the true position of the particles, although it 
would seem from the appearances presented that the tracts 
are not continuous through the entire length of the muscle, 
but are subdivided into longer or shorter portions. In the 
transversely striped fibre, these molecules are rendered 
more evident on the addition of water. 
Kolliker notices also the formation of vacuolar spaces in 
the interior of muscular fibre, under the influence of dilute 
saline solutions—as for instance of sulphate of soda of 83—7 
per cent. ‘These vacuoles, which contain a clear fluid, are dis- 
posed in longitudinal series, apparently occupying the spaces 
in which the above-described granular tracts are disposed. 
