STRIPED MUSCLE OF WASP 9 
EAR sa Oe ; 
Sane 
a Se 
ra 
AN 
<Q 
MEMS t= 
Sr 2s 
. » >. 
gar A 
So 
is 2 = E 
Bee 2/7 en I ee 
it BE 
Fic. 1. Illustration of fixed and hematoxylin-stained specimen of muscle 
fiber of Cassida equestris, showing at the left a lateral ‘contraction wave’ in- 
cluding eight ‘contraction bands’ (according to Rollet). At the right, at A, 
the writer has added two sarcomeres to illustrate his conception of the condition 
in the relaxed muscle fiber. The right-hand border of Rollet’s figure is, accord- 
ing to the writer’s interpretation, at midphase of contraction. The contraction 
band includes opposite halves of two successive Q-dises, the intervening N-dises, 
and the bisecting telophragma. There occurs during contraction a true reversal 
of striation as regards a deeply staining substance of the Q-dises and the con- 
traction bands. Illustrations of similar fibers viewed with the micropolariscope, 
show Q, N, and Z anistropic in nature; hence we may infer that Rollet regarded 
also the contraction band as anisotropic and interpreted the reversal of striation 
as the result of a change of position of the anisotropic substance of the Q-discs 
of the relaxed fiber. 
