ARREST OF DEVELOPMENT. 81 



and ulnar of both arms in an adult is preserved in the museum 

 of St. Thomas's Hospital. 



335. The right arm of the same foetus. The limb terminates 



just below the elbow in a stump like that of an amputa- 

 tion. 



The arm has been divided vertically to show the condition of 

 the internal parts. The humerus is perfect and articulates with 

 a piece of cartilage, which represents the upper extremity of the 

 ulna. The direction of this rudimentary olecranon is such that the 

 forearm, if developed, would be flexed at right angles to the arm. 

 The triceps and brachialis anticus are both seen in section. The 

 skin is stretched tightly over this olecranal cartilage, but it forms 

 a tubercle at its anterior extremity, an exceedingly rudimentary 

 representative of the forearm and hand." 



336. The left arm of the same foetus, in which the upper arm 



ends in a conical stump at the junction of the middle and 

 lower thirds of the humerus. A longitudinal section has 

 been made through it, to show the rounded termination 

 of the humerus and its relation to the integument. A 

 minute cutaneous knot represents the more anterior parts 

 of the limb. 



337. The left inferior extremity of the same foetus. All the 



parts below the condyles of the femur are represented by 

 a minute tubercle only on the outer side of a rounded 

 stump ; and this is formed by the skin, which is stretched 

 tightly over the inferior articular extremity of the femur. 

 The limb has been divided vertically. 



338. A Human full-time foetus, with the inferior extremities 



represented by button-shaped processes, and the position 

 of the superior extremities indicated by minute depres- 

 sions only. The left inferior extremity has been dis- 

 sected ; it is seen to consist of ligamentous tissue, into 

 which numerous irregular muscles arising from the pelvis 

 are inserted. The testes are abdominal, and there is an 

 excessive development of subcutaneous fat. 



Presented by C. J. White, Esq., 1870. 



c. Micromelia. 



This term has been applied to minute undeveloped limbs. 

 Examples are exceedingly rare. 



