633 



tinnk is innervated by means of the perforating branches of the 

 intercostal and lumbar nerves. 



If Til. 3 is taken to be tiie most cranial and L. 4 to be the most 

 candal nerve of the trnnk, it will be found that from Th. 3 to 

 Til. 7 each ner\e-root is sending three perforating branches to the 

 skin : a dorsal, a lateral, and a ventral branch. The dorsal nerve- 

 trunk generall}' supplies two main brandies: a medio-dorsal and a 

 dorso-lateral one. The lateral nerve invariably supplies two branches : 

 a latero-dorsal and a latero-ventral branch. The ventral nerve-trunk 

 usually consists of one main trunk, which may be said to be medio- 

 ventral. F'rom Th. 8 to L. 4 the medio-ventral branches are wanting: 

 their place is taken by the latero-ventral ones. 



The different points, w^liere the dorsal, latei'al, and ventral nerves 

 enter into the skin, may be interconnected by lines. This having 

 been done, it becomes evident that the dorsal branches, going in 

 a cranial-caudalward direction, perforate the fascia continually at 

 a greater distance from the raid-dorsal line, whilst the lateral trunks 

 on the contrary come forth more dorsalward. A correct insight into 

 the relations of these nerves is offered by Fig. 1. Fi'om Fig. 2 it 

 may be seen moreover, that the skin of the trunk can be divided, 

 according to a superficial scheme, into three zones as regards its 

 peripherical nerves: a dorsal, a lateral, and a ventral zone. 



\f ''~J ■'■■ (fcrsales d^y^^^^^ ■,.-^.- •'* 



Jtamj taferaks dJI^ftHn/e/Wifa/esSM. 5- 'Si' //_cuf''- 



cum J^.j>cc/ora//s Jcrsa/iólt/entr: ff^ („f - 



^ i I ^ •'^'^^^-^ 



Fig. 2 Extension-zones of the dorsal, lateral, and ventral nerve-branches of the 

 skin of dogs, according to Nahrich. 



1. The first question I now pnt to myself was the following: are 

 the perforating dorsal, lateral, and ventral trunks, which belong when 



42* 



