. Electro-physiology. Electrophysiology. ORGANISATION AND STRUCTURE OF MUSCLE 49 duced in during the It is also easy to see that ' the dark, sharply defined bands appear where the relaxed muscle presents the segments, (JZJ}, or (JNE, Z, E NJ), and that the light bands correspond essentially with the contracted strias (Q h Q). The muscle-fibres of insects, killed by strong alcohol, often exhibit local contractions (" fixed waves of contraction ") in which the histological changes pro- the striated fibrils transition from rest to contraction can be ascer- tained exactly by means of sta
. Electro-physiology. Electrophysiology. ORGANISATION AND STRUCTURE OF MUSCLE 49 duced in during the It is also easy to see that ' the dark, sharply defined bands appear where the relaxed muscle presents the segments, (JZJ}, or (JNE, Z, E NJ), and that the light bands correspond essentially with the contracted strias (Q h Q). The muscle-fibres of insects, killed by strong alcohol, often exhibit local contractions (" fixed waves of contraction ") in which the histological changes pro- the striated fibrils transition from rest to contraction can be ascer- tained exactly by means of staining methods and reagents. These very subtle manifestations are of the greatest theoretical interest, and must be discussed a little more fully. As before, we may accept the penetrating conclusions of Eollett (22). On examining a well-fixed wave of contraction, from a fibre of Otiorlnjnclius mastix stained with haematoxy- lin (Fig. 31), it is in the first place evident that the dark-blue band (C) of the contracted por- tion of the fibre, Nasse's " con- traction-disc," is derived from the transformation of the system (JNE,Z,ENJ), and is there- fore the same section which • __ Engelmann denotes as isotropous, and Eollett as the arimetabolous layer (a). In the relaxed arimetabolous layers the bands (Z} and (N] are deeply stained, the bands (E} and (J) not at all, or very slightly ; in the relaxed " metabolous " sections (Q h Q) (Engelmann's " anisotropous " layer), which Eollett denotes by //,, the ends of Q are more deeply stained than the centre h (Hensen's stripe). With increasing contraction of the section (a), the diminishing bands (N~) draw nearer and nearer to (Z), until at last the two E iMtimmttttmir. >»•••••»•••»•* «*«>*** / _ ,.'. T-jt i i) -111 rrv -,-•» frt jji j^ jjj< _^ Jj. _^ ^ !^t 'j t-^- i-u^ ff ,*'••*•*»•»»•»»»»*»»•» ' y c Q' C Fio. 31. — Muscle -fibre of Otiorhynchns
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