BY DR. KLEIN. 73 



disintegrated parts are separated from each other only by 

 short intervals of normal muscle. By drawing asunder a small 

 number of muscular bundles, their opposite ends being seized 

 with fine forceps, a preparation may be obtained which shows 

 similar appearances in a larger proportion of fibres. 



The extraordinary power of resistance of the sarcolemma 

 ma}' be shown as follows: One of the hind legs of a tadpole IB 

 amputated at the thigh. The animal is then replaced in water. 

 After forty-eight hours, the loosened muscular fibres hang from 

 the stump in long pencils. If these are cut off close to the sur- 

 face of the stump with sharp scissors, and covered in water, 

 the}' are found to consist of a number of hyaline tubes, which, 

 when seen in profile, present doubly contoured edges. Next 

 the cut edge some of them contain a plug of striped muscular 

 substance, or of coarsely granular material, which is divided 

 into a number of closely packed polyhedral cells. In the rest 

 of the tubes, coarsely granular young cells are seen sprouting 

 from the internal surface. 



Muscle- Corpuscles. In preparations of fresh muscle 

 (newt, frog, or Hydrophilus} numerous nuclei occur, which in 

 the Hydropliilus are roundish, in the frog oblong or staff- 

 shaped. If dilute acetic acid be added, the muscular substance 

 becomes swollen and transparent, and the nuclei are seen very 

 distinctly, each embedded in granular protoplasm,, which has 

 the form of a spindle-shaped cell, the long axis of which is 

 parallel to that of the fibre. If, on the other hand, we examine 

 an oblique or cross section of frozen muscle, covered in dilute 

 acetic acid, it is easy to satisfy one's self that the nuclei in 

 question are not embedded in fusiform protoplasmic masses, 

 but in finely granular lamellae, which are seen to be dotted 

 about the whole thickness of the fibre, and may be either di- 

 vided or simple. The distribution of these lamellae in the 

 muscular fibre differs in different animals. In mammalia, they 

 are confined to the immediate neighborhood of the surface; in 

 the Hydrophilus, crab, newt, and frog, they constitute a net- 

 work within the muscular fibre, exhibiting marked differences 

 in thickness, not only between different lamella?, but between dif- 

 ferent parts of the same lamella. In fresh muscle of Dytiscus 

 marginalia, the arrangement of these protoplasmic masses is as 

 follows: In some muscular fibres, the granular protoplasm has, 

 throughout the fibre, the form, more or less, of cylindrical bands. 

 in which roundish nuclei are arranged close together in linear 

 series. Here and there, these nuclei are separated by distinct 

 marks, so that the whole cylinder seems as if divided into por- 

 tions, each corresponding to a nucleus. In other fibres, there 

 are, in place of an 'axial cylinder of protoplasm, two or three 

 lamella? which are continuous with each other by subordinate 

 lamellae of various extent. In these, roundish nuclei are em- 



