80 LECTURE III. 



lowing a longitudinal direction, and these, indeed, in 

 some preparations preponderate to such a degree, that the 

 muscular fasciculus appears to be striated almost exclu- 

 sively in this direction. If now we add acetic acid, there 

 are forthwith disclosed immediately beneath the sheath, 

 and now and then also more towards the centre, nuclei 

 which are tolerably large, and mostly contain large nucle- 

 oli in greater or less number. In this manner, therefore, 

 after we have cleared up the internal substance by the 

 application of acetic acid, we again obtain an appearance 

 which reminds us of the original cell-form ; and there 

 has been the greater tendency to regard the whole of a 

 primitive fasciculus as having sprung from a single cell, 

 because according to the view which was formerly 

 entertained, the individual primitive fasciculi of every 

 muscle were thought to extend from the point of origin 

 to that of insertion, and were therefore held to be 

 as long as the muscle itself. This latter supposition 

 has, however, been shaken by investigations which 

 were set on foot in Vienna, under Briicke's direction 

 by Rollet, for he demonstrated that in the course of 

 muscles the ends of primitive fasciculi are to be seen 

 running into points, so that a primitive muscular fasci- 

 culus would comport itself like a large fibre-cell (Fig. 

 105, A). These ends fit one into the other, and, accord- 

 ing to this, the length of a primitive fasciculus would by 

 no means correspond to the whole extent of the muscle. 

 On the other hand, I must remark, that observations 

 have been made hi different quarters quite recently, 

 which are rather of a nature to throw doubts upon the 

 imi-cellular nature of these elements. Leydig regards 

 them as rather containing a series of cells of a smaller 

 kind, between which the contractile substance is lodged, 

 his idea being based upon the circumstance that every 

 nucleus (Figs. 23, b, c ; 24, B] is enclosed in a special 



