142 
other side it is known, that the cells of the sebaceous glands of 
the Mammalia contain eleidin-granules and can even partly undergo 
keratinisation *). One must indeed imagine the sebaceous cells 
to originate from ordinary epithelium-cells, which had already the 
capacity of keratinisation and it is not surprising that this capacity 
reappears now and then. 
So the femoral organs of Lacerta have arisen from cutaneous glands ; 
they have preserved the structure of those glands, chemically 
however they are modified, in connection with the strong kerati- 
nisation, which is characteristic of the skin of reptiles in general. 
If the femoral organs can be derived from cutaneous glands, one 
can imagine the same thing in the case of the hairs of mammals. 
Only in this case the differentiation has become greater and the 
structure of the organ is more complicated, in consequence of the 
more important function the hair has in the life of mammals. The 
hair papilla is to be considered of secondary origin and to have 
arisen in connection with the richer nutrition, which had become 
necessary for the stronger growth. 
But there is still another phenomenon that can be easily explained 
by this hypothesis. The origin of the hair as a solid epidermic 
thickening quite agrees with that of cutaneous glands, but also with 
that of the femoral organs, according to the descriptions of MAURER 
and ScHArgr. As to the thighorgans, the first author already directs 
the attention to this similarity with cutaneous glands of the amphi- 
bians, but attaches much importance to the difference between them, 
which lies in the fact that the smooth muscular fibres of the glands 
of the amphibians are absent in the femoral organs. In this point 
I cannot agree with him: these muscular fibres, which in the cutaneous 
glands are necessary for the extrusion of the secretion, are from 
their very nature superfluous in the entirely horny thighorgans, and 
so it is perfectly clear, that they have disappeared. And the same 
is true for the hairs, where they are absent as well. Another point, 
to which Maurer attaches much importance, is the peculiar arran- 
gement of the matrix-cells, which appears in the very first origin of 
the hair and of the dermal sense organ in the same manner. It 
seems to me however that this arrangement may be explained by 
the pressure of the surrounding cells upon the growing germ and 
so in different cases may appear in similar circumstances. 
Since the researches of Dr MriJere *) an attempt to explain the origin 
of the hair must take into consideration their arrangement on the skin. 
‘) Cf. Scuärer, Text-Book of Microscopic Anatomy, 1912, p. 476. 
8) Morph. Jahrb., XXI, 1894. 
