442 



Dr. W. Kiihne. On the 



suggested, is, at the same time, secreted in contact with the muscle, 

 we understand very well the necessity of direct contact, and in this case 

 it would suffice if the sublemmal nerve were to run in any form for a 

 short distance under the sarcolemma. The branching then would 

 mean the enlarging of the contact. But however rich and intricate 

 the ramifications may be, we can by no means say they display 

 throughout the principle of increase of superficies; on the contrary, 

 they are often astonishingly poor and small. As concerns their 

 form, they are not irregular, but so strikingly uniform that this 

 point deserves particular attention as being apparently indispensable 

 for innervation. 



Instead of describing the forms, allow me to show you the object 

 itself in a selection taken from the most diverse vertebrates. First 

 from the Amphibia (fig. 9) : rod- like branchings with long outstretched 

 twigs, a form which crops up again in a remarkable way in many 

 birds. The rule here is asymmetry of the divisions: all the twigs 

 have the form of a bayonet. 



Fig. 9. Fig. 10. 



The following preparation shows the termination in the dog (fig. 10). 

 Here the branches are crooked, and hence quite divergent, so that the 

 points of agreement with the form of the Amphibia are at first over- 

 looked. But if we examine the divisions, you will remark that these 

 are again unsymmetrical and give off branches whose ends lie very 

 diversely removed from the common place of origin. The ends are, 

 as a rule, turned towards each other, and often so approximated 

 that it is at times troublesome to find the gaps between them, and if 

 they do not lie in the same plane they appear to be united into a ring. 

 In other cases one end overlaps the other, but we then find that all 

 the points of the branches which are turned towards each other lie at 

 unequal distances from the nearest bifurcation. This law holds good 

 in all the thousand cases of motor endings thus far observed and 

 shows a strict order in the apparent chaos of these structures. And 

 yet among the organic forms there is scarcely one which varies so 

 much in other respects and often is so inextricably complicated as this. 



The drawings (fig, 11, from the muscles of the gainea-pig, and 

 fig. 12 of the rat) and a preparation from a lizard (fig. 13) may serve 



