206 



SPECIAL HISTOLOGY. 



surface. It was not before the seventh month that I perceived, in the 

 same situations, the first indications of the sweat-pores and ducts in the 



Fig. 81. 



epidermis, though as yet very indistinct, and the latter forming only 

 half a spiral turn (Fig. 82, A) ; at the same time the part of the gland 

 which projected into the corium was more considerably developed, 

 reached as far as the innermost portion of that structure, and at its 

 csecal extremity was bent into a hook or even slightly convoluted, so as 

 to afford the first indication of a glandular coil of about 0*04 to 0-06 of 

 a line. The canal arising from it usually presented several marked 

 undulations, and measured in total thickness 0-015-0-022 of a line, with 

 a cavity of 0-003-0-00-i of a line, which frequently extended even to 

 the terminal coil: like the latter it was composed of the original though 

 thickened membrane continuous with the surface of the corium, and of 

 an epithelium consisting of many layers of pale, polygonal, or rounded 

 cells. The glands of the rest of the body about this period, appeared 

 to me to be similarly constituted. I can say nothing as to their 

 earlier condition, but even those of the axilla were in no wise distin- 

 guished from the rest. From this time the development goes on very 

 rapidly ; the end of the gland elongates more and more, and coils itself 

 up (Fig. 82 B), so that it assumes an appearance hardly different from 

 that which it presents in the adult. In the new-born infant, the glan- 

 dular coils in the heel measure 0*06-0"07 of a line (in a child of four 

 months O'06-O-l of a line on the heel, in the hand 0'12 of a line), present 



Fig. 81. — Rudiment of a sudorij^arous gland of a human embryo at five months; magni- 

 fied 350 diameters: a, horny layer of the epidermis; 6, mucous layer; c, corium; d, rudimen- 

 tary glands, as yet without any cavity, and consisting of small round cells. 



Fig. 82. — .4, rudiment of a sudoriparous gland from a seven months' fcetus ; magnified 

 50 diameters. The letters a, b, d, as in Fig. 81. The cavity e is present throughout, only it 

 does not extend quite so far as the end of the thicker part of the rudiment of the gland, 

 which becomes converted into the glandular coils. The continuation of the canals into the 

 epidermis and the sweat-pores,/, are present. B, a coil of a sudoriparous gland, from a 

 fcetus at the eighth month. 



