84 



EIGHTH LECTURE. 



The former consist of sarcous elements (a*) placed nearer each 

 other. This may also be recognized without trouble by the 

 aid of good and strong magnifying powers. They are elon- 

 gated prismatic bodies, measuring 0.0017 nim. in the proteus, 

 0.0013 m the frog, o.ooii to 0.0012 mm. in the mammalia and 

 man. 



The sarcous elements must, naturally, be joined one to the 

 other. 



If we split off one of the finest longitudinal filaments, that 

 is a so-called muscular fibrilla (1), the longitudinal series of 

 sarcous elements (a) are held together by the transparent 

 longitudinal connecting medium (b). If we examine a mus- 

 cular filament split up into transverse plates, the dark and 

 light transverse zones are found to be connected by a trans- 

 verse connecting substance, which extends over the outer 

 surface from a and b of our Fig. 78, 2. Here the longitudinal 

 connection is naturally, completely dissolved. 



Up to about ten years ago, we thought the matter 

 might thus be passably explained ; but newer observa- 

 tions have been added and further 

 doubts have arisen. 



In the year 1863, the Englishman, 

 Martyn, had already seen a dark trans- 

 verse line in the transparent longitu- 

 dinal connecting medium. These ob- 

 servations were afterwards corroborat- 

 ed and extended by Krause (Fig. 79). 

 Let us name this thing (a), therefore, 

 Krause's transverse line or disc. 



But with this we have still not 

 reached the end. At the same time 

 another competent investigator, Hen- 

 sen, found the dark transverse zone, the 

 transverse series of sarcous elements, 

 divided by a transparent transverse 

 This is the Hensen's middle disc. Granules which 



Fig. 79. — Krause's transverse 

 discs ; a, a, i, a muscular fibrilla 

 without; 2, one with strong longi- 

 tudinal traction, both very strong- 

 ly enlarged (Martyn) ; 3, muscu- 

 lar filament of the dog imme- 

 diately after death. 



line. 



were contiguous above and below to Krause's transverse line 



