THE CAROTID ARTERIES IN THE RABBIT 105 



arteries have been slightly displaced from the usual position of 

 either. In one case (figure 6), it is interesting to note that the ex- 

 ternal maxillary is given off as a branch of the internal maxillary 

 artery some distance cephalad of the latter's junction with the su- 

 perficial temporal. In this case it occupies the relative position of 

 the inferior alveola branch, and might easily have been taken for the 

 latter on superficial examination, the inferior alveola branch in this 

 case being somewhat more cephalad than usual. In two cases, how- 

 ever, figures 4 and 5, where the maxillary and lingual branches are 

 closely approximated, the inferior alveola branch is considerablv 

 more caudad than is ordinarily the case. 



The Internal Maxillary-Superficial Temporal differences — In 

 some instances these two vessels differ conspicuously in size, and 

 where this condition is most marked, one may be considered a 

 branch of the other. In conditions shown in figures 2 and 3, the 

 superficial temporal is a small side branch passing dorsad while the 

 larger internal maxillary artery continues forward. In other cases 

 (figure 9) the opposite is true, the smaller internal maxilliary artery 

 is a branch of the larger superficial temporal trunk, and in this case 

 its point of origin from the temporal is well cephalad. 



In two cases represented by figure 7, the relationship of these 

 terminal branches of the external carotid artery are of interest since 

 they together with the external maxillary artery form a three parted 

 fork, the external maxillary artery turns abruptly ventral, the super- 

 ficial temporal passes dorsad, and the internal maxillary bends mesad. 

 In size there is very little difference between the three vessels, any 

 one of which could be considered a terminal branch of the external 

 carotid artery. 



The Superficial Temporal-Occipital differences — In three cases 

 the occipital artery originates as a branch of the superficial temporal. 

 In one individual (figure 9) it passes dorsad from what may be con- 

 sidered the base of the superficial temporal or its innominate. In 

 figure 5 it is but a little more cephalad, while in figure 10 it is shown 

 passing away from the temporal well cephalad to the latter's junc- 

 tion with the other arteries. 



Other differences — In one case shown in figure 11, all the arteries 

 pass forward away from the common trunk in such a way as to 

 form a sort of corona radiata. In such a condition the external 

 carotid artery is practically eliminated, since the common carotid 

 artery is broken up immediately into five terminal branches. In the 

 condition shown in figure 12 the common carotid artery can be con- 

 sidered as terminating in three innominate trunks ; one giving rise 



