taining no bone. It was covered with normal skin, contain- [97] 

 ing fine hairs, and was apparently well vascularized. Three 

 distinct portions or segments conld be made out. The basal 

 piece was short and on the dorsal side scarcely marked off 

 from the next following, except when the tail was in a state 

 of contraction (Fig. 2). On the ventral side a transverse 

 furrow separated it from the next portion. The middle seg- 

 ment had a length of 25 mm., was curved a little to the right 

 and tapered somewhat towards its distal end, where the much 

 more slender end-segment was attached. These two portions 

 were separated by a constriction more marked on the left side. 

 The terminal segment curved to the right and ventrally and 

 ended in a rounded blunt extremity. On the whole, the tail 

 gave an impression not unlike that of a pig's tail, a similarity 

 which has been noted in a number of cases previously re- 

 ported. 



The hairs upon the tail, which were considerable in num- 

 ber, were plainly visible to the unaided eye. They pointed . 

 towards the tip, as could readily be confirmed by examination 

 of longitudinal sections (Fig. 4). The convergence of the 

 hairs towards the tip of the tail corresponds with the arrange- 

 ment of the hairs in the cocc3^geal whorl {vertex coccygeus of 

 Ecker), found in normal, i. e. tailless individuals, and sup- 

 posed to be a vestige of the embryonic tail. 



Two weeks after the birth of the child the tail was 4.4 cm. 

 long; at the age of two months it had grown to 5 cm.; and at 

 six months, when it was removed, it had attained the length 

 of 7.0 cm., showing altogether a fairly rapid rate of growth. 



The most remarkable characteristic of the tail was its 

 movability. When at rest it would lie extended in the mid- 

 line (Fig. 1), or bent over to one side upon the buttocks. 

 The mother of the child said that she had seen the tail bent 

 through an angle of 180°, its tip pointing towards the head. 

 It must, however, have been brought into this position pas- 

 sively, for, as will be seen later, there was nothing in the 

 arrangement of its muscles which could account for this. 

 When the child was irritated, and cried or coughed, the tail 

 would contract markedly. Between the basal and middle 



(5) 



