338 MR. J. B. SUTTON ON THE INTERVERTEBRAL [June 29, 



in a paper published in the ' Journal of Anatomy and Physiology ' for 

 January of the present year. The object of this paper was to draw 

 attention to the circumstance that if a section be carried vertically 

 through the long axis of the second vertebra in an adult there will 

 be found in the majority of cases a small strip of cartilage occupying 

 the position indicated in the drawing (fig. I). 



Prof. Cunningham states that whilst engaged in an investigation 

 into the curves of the spinal column in Man and the Apes he made 

 mesial sections of a large number of frozen human spines. His 



Fig. 1. 



A vertical section through the body of the axis to show the lenticular-shaped 

 piece of cartilage, c. 



attention was attracted to a small lenticular-shaped plate of cartilage, 

 which seemed in almost every case to be interposed between the os 

 odontoideum and the body of the axis vertebra ; on all sides it was 

 surrounded by bone, so that it could only be brought into view by 

 means of sections. 



The observations were made on eighteen axis vertebrae, but three 

 were eliminated on account of difficulty in ascertaining the age 

 of the subjects. The fifteen remaining specimens were divided into 

 three groups according to their age. 



The first group comprised six axes, two from females and four from 

 males, varying in age from twenty-four to fifty. In all the cartilage 

 was present, measuring 4 mm. in length and 2 mm. in thickness. 



The second set comprised three specimens from females, varying 

 in age from fifty to sixty years. The cartilage was present, and of 

 the same dimensions as in the younger bones in the previous set. 



The tiiird group consisted of six examples, two males and four 

 females, the limits of age being from, sixty to seventy. In four of 

 the axes the lenticular disk was present, and measured in length 

 3 mm. and in width 1| mm. In the two oldest examples the disk 

 was absent. 



The cartilage in the youngest specimen, a girl aged twenty-four 

 years, was found to be of the hyaline type, with evidence in some of 

 the sections of a sluggish ossific process around the margin ; but 

 remains of the notochord could not be detected. 



