TAIL-LIKE FORMATIONS IN MEN. 



353 



Fig. 5. — Coccygeal Hair-tuft. From Ecker. 



forward that the point of the nearly straight-running coccyx is 

 pushed against the skin and lifts it up. Inversion has at this 

 time not yet taken place. 



From the third to the fourth month the human foetus receives 

 its clothing of wool-hairs, which penetrate obliquely through the 

 skin, and form hair-lines converging against the tips of the coc- 

 cygeal lump, and represent there a vertebra. This vertebra — vertex 

 coccygeus — constitutes in sev- 

 eral cases observed and de- j^- ^ ' ''"* 

 scribed by Ecker and other 

 investigators (Fig. 5) an evi- 

 dent pencil of longer hairs^ a 

 real hair-taillet, such as Gre- 

 cian art gave at the same point 

 to fauns and satyrs. It has al- 

 ready been shown by Eschricht 

 that the converging hair-tuft 

 in the region of the coccyx is 

 analogous to the similar arrangement of hairs on the tails of the 

 mammalia. Chr. A. Voight has expressly noticed the same rela- 

 tion in his treatise on the direction of hairs on the human body 

 (Denkschrift of the Vienna Academy, 185G). " The parts of the 

 skin on which converging tufts are formed," he says, " are either 

 places which were quite bare in the earlier periods of development, 

 or they are spots that covered the prominent bones (or cartilages), 

 the strongly growing parts, like the coccyx, the elbows, and the 

 tip of the ear in animals, or every place toward which an exten- 

 sion of the skin was taking place or had taken place at the time of 

 the development of the hair." This author remarks especially 

 of the coccyx-tuft that, as the hairs become longer, they rise over 

 the surface and form spiral-shaped hair-tufts, like the brushes on 

 the tips of the tails of animals. There is thus again shown a 

 plain original connection between the formation of the tail-shaped 

 attachment and the coccygeal hair-tuft. 



There is usually found in the human foetus, above the coccygeal 

 vertebra, a hairless spot, the glabella coccygea, under which often 

 appears later, and is even perceptible in persons of middle age. a 

 depression of greater or less depth, i\\e foveola coccygea, over the 

 origin and significance of which many and often curious hypothe- 

 ses have been set forth. It was described by Lawson Tait, in a 

 paper read before the Anatomical and Physiological Section of the 

 British Association in 1878. He had found from the examination 

 of several hundred persons that only fifty-five per cent of them 

 were without traces of the depression or "sacral dimple," while 

 it was faintly marked in twenty-two per cent, and well marked in 

 twenty-three per cent. But it seemed to become imperceptible 



