62 H. E. JORDAN 
PLATE 1 
EXPLANATION OF FIGURES 
Leg muscle of wasp 
(Unless otherwise specified all subsequent drawings are from tissue fixed 
in 95 per cent alcohol, stained with iron-hematoxylin and magnified about 1300 
diameters. ) 
14 Portion of longitudinal section of a fiber, in the relaxed condition, show- 
ing the Q- and J-dises, and on either side of the telophragma (Z) the N-dises. 
15 Fiber in early stage of contraction, showing the terminal knobbed con- 
dition of the Q-segments of the myofibrils, indicating a passage of deeply staining 
substance toward the telophragmata and the appearance of the bisecting H-disc. 
16 Fiber in the relaxed condition, only lightly stained, showing the axial 
arrangement of the long columns of realtively small nuclei. 
17 Transverse section of fiber, ‘showing a central nucleus, the lamellar 
character of the ‘sarcostyles’ and the enveloping sarcolemma. 
18 Fiber fixed in Flemming’s fluid and destained to a point where the Q-dise 
is no longer conspicuous, to show the smaller spherical J-sarcosomes on either 
side of the telophragma, and the large oval Q-sarcosomes. 
19 Fiber at alate stage of contraction, in which opposite halves of successive 
Q-dises (as regards their deeply staining substance) have fused with each other, 
and with the intervening N-discs, against the telophragmata to form contraction 
bands. 
20 Fully contracted fiber, showing seven contraction bands. 
Wing muscle 
21 Portion of longitudinal section of five adjacent sarcostyles with six groups 
of sarcosomes, and one nucleus (nu). The telophragmata of the several sarco- 
styles are at the same levels, indicating intersarcostylic continuity. Flemming 
fixation; lightly stained. 
22 Two adjacent sarcostyles showing a continuity of the telophragmata, in 
the region near the middle where the fibrils have been only very slightly drawn 
apart. Flemming fixation. 
23 Five adjacent sarcostyles with four extensive groups of intervening sarco- 
somes. On the sarcostyles are seen both the coarser, deeper staining telophrag- 
mata and the more delicate, fainter mesophragmata. The narrower intersar- 
costylic spaces contain single rows of sarcosomes; the wider, double rows. The 
long axis of the sarcosomes of these two groups are in general placed respectively 
at right angles and parallel to the long axis of the sarcostyles. Flemming 
fixation. X 2600. 
24 Three common forms of sarcosomes as seen in longitudinal sections of the 
wing muscle. X 2600. 
