STRIPED MUSCLE OF WASP 65 
PLATE 2 
EXPLANATION OF FIGURES 
25 Fresh relaxed sarcostyle as seen in Ringer’s or Toison’s solutions. The 
telophragmata are conspicuous, the dark discs are thick, the light discs very 
thin. 
26 Relaxed sarcostyle fixed in, Flemming’s fluid and lightly stained with 
iron-hematoxylin. This technic causes only very slight modification as com- 
pared with the fresh fibril in Ringer’s solution. 
27 Relaxed sarcostyle fixed in 95 per cent alcohol and stained with iron- 
hematoxylin. The fibril as a whole is shrunken; the dark dise also is greatly 
shrunken, due to dehydration, and stains deeply. 
28 Relaxed sarcostyle fixed in a 10 per cent formalin solution and lightly 
stained with iron-hematoxylin. Both the telophragmata and the fainter meso- 
phragmata are visible. The fibril appears swollen at the levels of the telo- 
phragmata. This apparent swelling is due to greater shrinkage in the regions of 
the mesophragmata and a relatively greater rigidity of the telophragmata. 
29 Fresh relaxed sarcostyle as seen after brief treatment with distilled 
water. The fibril becomes beaded, and slightly shortened, due to the relative 
rigidity of the telophragmata and the endosmosis suffered by the sarcomeres. 
The Q-disc is relatively thin. After prolonged immersion in distilled water the 
Q-dise appears to fill the entire sarcomere due to its dilution, and the sarco- 
meres eventually rupture. These phenomena demonstrate the presence of a 
perisarcostylic membrane. 
30 Sarcostyle imperfectly stained, from a preparation according to Rollet’s 
method. This fibril has suffered the same modification as one placed in distilled 
water or other hypotonic solution, but in exaggerated degree due to the action 
of the formic acid. 
31 Resting sarcostyle, properly stained, from the same preparation as 
figure 30. This fibril has, moreover, been slightly compressed under the cover- 
glass. It is similar to the fibrils, figures 29 and 30; also to Schaefer’s fibril A, 
figure 6, and represents a sarcostyle artificially contracted, that is, swollen and 
consequently shortened, through the osmotic action (endosmosis) of the hypo- 
tonic aqueous formic-acid solution employed in Rollet’s technic. 
32 Sarcostyle at somewhat later stage of endosmosis than that of figure 31, 
in which the darker Q-substance has become diluted to an extent where it slightly 
discolors the entire beaded fibril. The last three figures demonstrate that the 
telophragma, while a relatively inextensible membrane, has a slight amount of 
elasticity. Comparison of figures 25 and 26 with figures 29 and 32 shows that 
the beaded condition of the sarcostyle represents an artifact. 
33 Contracted sarcostyle from a fresh preparation in Ringer’s solution 
(compare with figs. 8, 20, and 44). The contraction bands appear double. The 
telophragmata are not conspicuous, probably in consequence of their stretched 
condition in the contracted, that is radially widened, sarcostyle. 
34 Sarcostyle of eyed elater (Alaus oculatus) at an early phase of con- 
traction. The sarcomere is constricted in the region of the H-dise in conse- 
quence of the dehydrating action of the alcoholic fixation. Iron-hematoxylin 
stain. 
