180 



MR. J. B. SUTTON ON THE 



[Mar. 18, 



This form of the disease is most frequent among the smaller 

 mammals, e.g. those of the genera Canis, Cynictis, IcJmeumon, &c. 



b. Late Rickets (Rickets occurring at puberty). — At the age of 

 puberty the disease presents certain peculiar features. In the first 

 place it does not tend to generalize itself as in the form just con- 

 sidered, for It may attack the axial skeleton only, and in some cases 

 affects the skull alone. The deformity is not so marked as in 

 rickets of infancy. 



Fig. 2. 



A longitudinal section through the last dorsal and first lumbar vertebra of a 

 Lion affected ivith " late rickets." It shows the proliferation of the 

 tissue in the neighbourhood of the epiphysial plate, and the abnormal 

 size of the intervertebral disk, bulging into the neural canal and com- 

 pressing the sjiinal cord. 



Its chief features are as follows : — Beading at the costal junctions 

 is fairly constant. If the epiphysial cartilages are affected, the 

 spongioid tissue is wanting, and a small quantity of fibrous tissue 

 developes in its place ; the line of the epiphysis is irregular. On this 

 I place considerable importance as a sign of disease. 



If the epiphysial plates of the vertebr.-e become affected, and this 

 they are very prone to do, the proliferation may give rise to pressure 

 on the spinal cord, and subsequent paraplegia as shown in the 

 drawing (fig. 2), taken from a nearly full-grown Lion affected with 

 this form of the disease. 



Hypertrophy of the skull-vault is very common ; it may exceed 

 the usual thickness five or six times, the base of the cranium re- 

 maining unaffected. The teeth are large, defective in number, and 



