76 ABNORMAL CONDITIONS OF THE LIMBS. 



Class IV. ARREST OF GROWTH. 



Although arrest of growth and arrest of development affecting 

 the limbs very frequently occur together, and one is either the 

 result or cause of the other, yet there are certain forms of arrest 

 of growth giving rise to great shortening of the limbs, brachy- 

 melia, which are not accompanied by any obvious arrest of de- 

 velopment. In brachymelia the bones are usually exceedingly 

 well ossified, but there is frequently deformity from irregular 

 contraction of the muscles, as well as great hypertrophy of the 

 subcutaneous tissue. Arrested growth is sometimes confined to 

 the digits, and is more frequent in the forearm and leg than in 

 the arm and thigh. When the whole of the lower limbs is 

 affected, the pelvic girdle is also usually of small size. Arrest 

 of the forearm or leg gives rise to considerable modification in 

 the arrangements of the muscles ; the flexors and extensors of 

 the digits in these cases usually arise from the shaft of the hu- 

 merus or femur. 



A. In the Digits. 



315. The left hind foot of a Pig in which the third digit is 



shortened by arrest of growth. It is worthy of remark 

 that in the Solidungula this is the only functional digit. 



Hunterian. 



316. The other hind foot of the same animal with more con- 



siderable defect of the corresponding toe. Hunterian. 



317. The left hand of a Human infant at birth with considerable 



shortening of the fingers. The ungual phalanges and the 

 nails are much smaller than is normal. The thumb is 

 short and thick, but its terminal phalanx is not abnor- 

 mally defective. The mother had a similar malformation. 

 Presented by R. Partridge, Esq., 1868. 



B. In the Limbs. 



Syn. Nanomelus, Gurlt. 

 Phocomele, Geoff. 



318. A foetal bitch Puppy with extreme shortening of all four 



extremities and arrest of growth in the posterior portion 

 of the trunk. Hunterian. 



