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 oceupying 
the position indicated in the drawing (fig. 1). 
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 vertebra, 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 third 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. 
