THE CAROTID ARTERIES AND THEIR RELATION TO THE CIRCLE 
OF WILLIS IN THE CAT. 
BY H. W. NOEEIS. 
The value of the domestic cat as an object of dissection in work intro- 
ductory to comparative anatomy in general and to mammalian anatomy 
in particular, makes it important that our knowledge of this form should 
be as exact as possible. 
Of the comparatively few works that deal specifically with the anat- 
omy of the cat only three attempt any detailed description of the smaller 
subdivisions of the carotid arteries. These descriptions are so at vari- 
ance with each other and with the actual structures as found by the 
writer that it would seem that in some cases they must be based upon 
individual variations or aberrant conditions. That blood vessels in 
general are subject to great variations In their individual relations is 
well known. This is as certainly true of the carotid arteries as of 
other blood vessels. This paper is based upon specimens whose arteries 
were injected through the dorsal aorta with chrome yellow starch injec- 
tion mass. They were prepared for ordinary student dissection and not 
for any special investigation. 
One of the most striking characteristics of the published descriptions 
of the carotid arteries of the cat is the contradictory statements made 
regarding the origin and distribution of their branches. According 
to MivarR the internal carotid artery is “a very minute vessel” that 
arises from the common carotid, passes into “a slender canal 
between the basi-occipital and basi-sphenoid, and the adjacent part of 
the temporal bone”, and enters the cranial cavity by the middle lacerated 
foramen. Reighard and Jennings^ state that it arises near or in com- 
mon with the occipital artery, passes anteriorly along the ventral border 
of the auditory bulla, and enters the latter together with the Eustachian 
tube, to pass into the skull by the middle lacerated foramen. Wilder 
and Gage=^ say that the internal carotid “passes along the carotid canal 
and unites with a larger vessel extending along the mesal side of the 
bulla”. Tandler'^ states that by a common trunk from the common 
carotid there arise three arteries: the internal carotid, the occipital, and 
the ascending pharyngeal. He is essentially in agreement with Mivart 
as to the passage of the internal carotid through the bulla into the skull. 
The internal carotid artery of Reighard and Jennings is the ascending 
1 . Mivart, St. George. The Cat. New York, 1881. 
2. Reighard, J. and Jennings, H. S. Anatomy of the Cat. New York, 1901. 
3. Wilder, Burt G. and Gage, Simon H. Anatomical Technology as applied 
to the Domestic Cat. New York, 1886. 
4. Tandler, J. Zur vergleichenden Anatomie der Kopfarterien bei den Mam- 
malia. Denkschr. d. Math-Naturw'iss. Classe d. kaiserl. Akad. d. Wissensch. 
Wien, Bd. LXVII, 1898. 
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