TEGUMENTAL ORGANS 5 



sixth month, the whole body of the embryo, except the surface 

 of the hands and feet, the red edges of the lips, the glans penis 

 and clitoridis, and the inner surface of the foreskin, is covered 

 with abundant soft woolly hair (lanugo). 1 



In certain parts of the body the hairs are arranged closely 

 and quite regularly in tracts, just as birds' feathers are arranged 

 in the so-called "pteryloc." These hair- tracts (Fig. 2) are vortex- 

 like in arrangement, diverging over some areas, converging over 

 others. 



In the former (cf. the hair of the head) the hairs point with 

 their free ends outwards, from the vertex as a centre ; in the latter, 

 on the other hand, the direction of the hairs is the reverse of this, 

 their free ends being directed inwards, i.e. towards the centre of 

 the vortex. This latter, converging, disposition is only found, both 

 in the lower Mammals and in Man, at parts where an organ either 

 projects during life, as in the case of horns and antlers, or has pro- 

 jected at some period in ontogenetic or phylogenetic development. 



An excellent example of this is afforded by the radial 

 arrangement of hairs often found in the male sex in the region 

 of the navel, or still better by the "vertex coccygeus" (Fig. 3) 

 described by Ecker. The position of this latter exactly corre- 

 sponds in the embryo with the point at which, before the bending 

 of the os sacrum took place, the extremity of the coccyx pushed 

 against the skin ; i.e. with the point where the coccyx formerly 

 projected as a free tail, the cauda humana (cf, pp. 2*7, 28). 



Just before birth the position of the vertex coccygeus shifts, 

 a hairless area being developed (Glabella coccygea) which may 

 sink in to form a pit (Foveola coccygea, fv, Fig. 4) (Ecker). On 

 the other hand it frequently attains such a degree of development, 



deutsehen) and of Holland (Niederdeutschen), I am convinced that "on his toes" 

 (Zehen) is the light version of the proverb, and not "on his teeth" (Zahnen). 



Many similar perversions of old popular sayings, or of words of which the original 

 meaning has gradually been lost in later generations, are to be found ; for instance, 

 the expression "to have his sheep (Schaffchen) in the dry " originated on the coast, 

 where "to have his ship (Schiffchen) in the dry" is still heard. Again, the 

 Schbnberg near Freiburg was originally called Schynberg, from Schyn, which means 

 a witch, a word which has been retained in the " Witch's Valley " at the foot of this 

 hill, and in the Swabian term of contempt " Schyn- Aas" (literally witch carcase). 



1 In the fourth or fifth month the human embryo has a distinct stratum corneum 

 with an epidermal layer outside it, which corresponds with the epitrichium of Rep- 

 tiles and of many Mammalian embryos (Edentata, Dicotyles, Sus, and others). After 

 the sixth month of embryonic life the latter disappears from most parts of the body. 

 The epitrichial layer covers the hairs and the glands, being able to some extent to 

 keep back the secretions of the latter. In this way it provides for the accumulation 

 of a rich secretory deposit, the so-called "vernix caseosa." 



