18 H. E. JORDAN 
toward the middle, as it appears with uncrossed (B) and with 
crossed (A) nicols, respectively. But the illustration does not 
give convincing proof that the bulged middle portion is actually 
contracted. This area suggests rather a distortion. Skepticism 
regarding a genuine contraction is further aroused by the fact 
5 
Fig. 5 Photomicrographs of portion of a leg-muscle fiber of Chrysomela 
coerulea, with ‘fixed contraction wave,’ as seen under the polarizing microscope. 
Fiber A was photographed with crossed nicols, fiber B with uncrossed nicols 
(from Schaefer, after Englemann). These photographs are interpreted by 
Schaefer as demonstrating that there is no change of position of the anisotropic 
substance of the Q-dise during contraction, hence no true reversal of striation. 
Schaefer claims that the same fact can be demonstrated in sarcostyles of wasp’s 
wing muscle treated according to Rollet’s technic (compare fig. 6). Schaefer 
accordingly makes the unwarranted assumption that the deeply staining sub- 
stance of the dark dise is identical with specific anisotropic materials of the 
sarcoplasm. 
that the anisotropic bands in the area interpreted as contracted 
are quite as sharp and distinct as those of the relaxed terminal 
regions, whereas most investigators agree that the anisotropy 
of a contracted fiber is relatively feeble. However, this illus- 
