OBSERVATIONS ON STRIPED AND UNSTRIPED MUSCLE. 77 



20 parts glycerine, and 20 parts water. This method brought 

 out the longitudinal striae. On treating gold preparations as 

 above and subsequently treating with 1 per cent, potassium 

 cyanide, he states that the sarcolemma gives way and the con- 

 tents escape, partly as fine particles and partly in larger pieces ; 

 in such pieces the transparent substance bounding Cohnheim's 

 areas was stained red, and was thickened at the nodal points. 

 The muscle-corpuscles always lay in the stained substance and 

 not in Cohnheim's areas; they consisted of a central oval nucleus 

 and a stained peripheral substance continuous with the stained 

 network of longitudinal strise. He states that the longitudinal 

 strise are very variable in thickness and always zigzag; never 

 straight. He regards them as thickenings of fine sheaths of 

 nervous matter enclosing the fibrillse of the muscle ; these 

 sheaths corresponding to the boundaries of Cohnheira areas. 



He therefore concludes that the intravaginal nerve plexus 

 and the longitudinal strise are continuous, and together make 

 up the isotropous part of the muscle-fibre, and are to be con- 

 sidered as nervous. To them belong also the muscle-corpuscles 

 and the nuclei of the intravaginal nerves. He regards the 

 anisotropous matrix as the contractile part. Gerlach thus 

 appears to view the isotropous part of the muscle, stained by 

 the gold, as a honeycomb and not a true network of fibrils. 

 He has apparently failed to observe the transverse networks, 

 and does not attempt to explain the relation between the 

 network and the transverse striation. 



The existence of an intravaginal nerve plexus in the muscle- 

 fibre, and also the continuity of the nerve end plate with the 

 isotropous part of the muscle, have been denied by Ewald 1 and 

 Fischer. 2 



Engelmann 3 regarded the isotropous part of the fibre as a 

 structure " das in Physiologisches Hinsicht von einem Nerven 

 nicht wesentlich abweichen Wunde," and suspected a connec- 

 tion with the axis cylinder. 



1 « Arch, fur Mikr. Anat.,' Bd. xiii, pp. 365—390. 

 s ' Pfliiger's Archiv,' Bd. xii, pp. 529—548. 

 3 ' Pfliiger's Archiv,' Bd. xi, p. 462. 



