ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
195 
Influence of Heat and Light on Pigmentation of Salamander 
Larvae.* — Professor W. Flemming finds that lighter pigmentation of 
salamander larvae may be induced ley increased temperature (Fischel), as 
well as by increased illumination (Flemming). The experiment was as 
follows : — 
I. (a) A number of larvae, in a cellar at 4°-5° C., in a white vessel in 
the window. Result in 8 days — light brownish colour. 
( b ) In a grey, covered vessel, in same cellar in the dark. Result in 
8 days — as dark as usual. 
II. (a) A number in a warm room (19°-20° C.), in a white vessel in the 
window. Result in 8 days — the lightest larvae. 
( b ) In a brown, half-covered stoneware vessel, in the same room. 
Result in 8 days — light-brownish colour as in I (.a). 
Hypertrichosis. f — Prof. A. Brandt has written an interesting essay 
on so-called dog-men, or more technically on hypertrichosis universalis. 
We refer to it merely in respect of its aetiological interest. The abnormal 
hairiness is regarded by some, e.g. Yirchow, Bartels, and Waldeyer, as a 
post-embryonic growth ; it is regarded by others, e.g. Darwin, von Sie- 
bold, Ecker, Unna, as a persistence and exaggeration of the lanugo 
foetalis. Brandt’s view is that an inhibitory influence, weakening the 
integumentary system, results in a hypertrichosis lanuginosa foetalis , the 
primitive hairs remaining, like the antlers on a castrated stag. The 
same weakness which caused the retention of the primitive hair may also 
express itself in defective dentition. Brandt recognises, however, that 
another kind of hypertrichosis may result from an exaggerated formative 
activity in the skin. But the two states are quite distinct. 
Viragines.'j — Prof. A. Brandt discusses the aetiological significance 
of the beard in Yiragines, which some — e.g. Kennel — interpret as a re- 
version-phenomenon, which the author, on the other hand, regards as a 
prophetic variation, expressing a tendency on the female’s part to gain a 
characteristic which many males have long since acquired. 
Epidermis Folds on Palms and Soles of Primates.§ — Dr. H. H. 
Wilder concludes that the callous pads on the feet of walking pentadac- 
tylous mammals become reduced in certain monkeys to fleshy mounds 
without definite boundaries. Over these mounds the folds, which are 
elsewhere approximately parallel, are distorted (from this primitive 
pattern) into whorls, spirals, or loops. In some Primates, including 
man, the mounds are reduced, so that only the epidermic figure or centre 
is left, or even that may disappear. In man the apical centres on the 
finger tips are fairly constant, Galton’s “ simple arch ” being the most 
reduced form. The palmar, thenar, and hypothenar centres are of un- 
certain occurrence. 
As a working hypothesis, Wilder suggests that the epidermic ridges 
were primitively even and parallel ; that pads evoked by pressure caused 
divergence of the primary ridges and the formation of secondary ridges y 
and that in modern walking forms the hypertrophy of the epidermis has 
obliterated the markings, which arboreal life has retained in the Primates. 
* Arch. f. Mikr. Anat., xlviii. (1897) pp. 690-2. 
t Biol. Centralbl., xvii. (1897) pp. 161-79. % Tom. cit., pp. 226-39. 
§ Anat. Anzeig., xiii. (1897) pp. 250-56. 
