32 FISTULA AND POLL-EVIL 
the cervical region. The posterior branches 
pass upward between the dorso-scapular liga- 
ment and the rhomboideus and thence to the 
superficial muscles and skin. These radicals 
are normally small vessels, but in old fistule 
they are often enlarged into arteries of a 
formidable capacity. The main trunk lying 
deeply in the base of the withers is seldom 
exposed in surgical operations. The variation 
in the distribution of these branches and 
especially the enlargement of some of them 
under the influence of disease make the study 
of the blood supply of the withers somewhat 
unsatisfactory from the surgical standpoint. 
There is always a pronounced difference in the 
amount of bleeding produced from incisions 
of exactly the same kind. 
The extra-thoracic distribution of the deep 
cervical artery.—Kmerging from the first 
intercostal space, it passes upward and for- 
ward between the lamellar portion of the 
ligamentum nuche and the complexus. It 
destination is the region of the poll where it 
anastomoses with branches of the occipital. 
Along its course along the neck it exhibits free 
communications with the vertebral and sup- 
plies by lateral branches the lateral cervical 
muscles. These lateral branches of the deep 
cervical which enter the splenius and serratus 
