ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
275 
Influence of the Gradual Cooling of the Globe on Evolution.* * * § — 
M. 11. Quinton believes that the general cooling of the globe has been a 
factor of capital importance in animal evolution. Those forms have 
succeeded which have been best able to sustain their internal tempera- 
ture. Thus the bird’s organisation is in this respect far superior to that 
of Mammals ; and the class is much more successful. Even in detail, in 
a particular series, say of Mammals, the progressive perfecting of the 
respiratory system can be traced. 
Evolution of Head-Scales in Boidse.j — Dr. H. C. E. Zacharias has 
made a study of this subject, which we cite here for its evidence of <£ a 
hundred per cent, variability ” — no two cases being the same — and for its 
theory of the import of movements and pressure as determinants in the 
evolution of scales in general. 
Function of the Lateral Organs.^ — Dr. H. Stahr relates his observa- 
tions on the habits of Toly acanthus ( Macropus ) viridiauratus — the well- 
known Chinese Macropod — particularly as regards their sexual by-play. 
He was much impressed by the part which tactile sensations seemed to 
play as sexual stimuli, and his suggestion is that an important function 
of the lateral line system may be to receive stimuli produced by the 
elaborate movements. As he says, the sexes communicate with one 
another partly by the lateral organs. 
Freshwater Fauna of South Africa.§ — Prof. Max Weber gives some 
of the results of his exploration in 1894, especially as regards the fresh- 
water fishes, molluscs, and crustaceans. He begins with a brief sketch 
of the different regions — Savanna, Erica or Protea, Karroo, and Kala- 
hari — with particular reference to the fauna. One of the peculiar con- 
ditions is, what may be called the periodicity of many of the rivers ; one 
of the most striking and doubtless correlated results is the sparseness of 
the freshwater fauna. 
Weberclassifi.es the freshwater fauna as follows : — 
1. Universal freshwater animals. 
2. Pegional freshwater animals. 
a. Local or autochthonous. 
h. Of marine origin, (1) relicts, and (2) immigrants. 
The south-west portion of South Africa has faunistic peculiarities 
which point (a) to an ancient independence (and connection with other 
circumpolar southern regions), and (h) to a subsequent union with the 
rest of Africa by which the faunistic unity has been lost. 
New Amphioxus.|| — Dr. A. Willey notes among his zoological ob- 
servations in the South Pacific, the occurrence of a new lancelet — 
Asymmetron caudatum sp. n. It seems more closely allied to A. Incay- 
anum Andrews — located upwards of 8000 miles away in the Bahamas — 
than to its relatives in Torres Straits, less than 600 miles away. 
The characteristic generic features verified in this new species are 
the following. The right metapleur is continuous with the ventral 
fin ; the latter has no fin-chambers and no fin-rays ; the right and left 
* Comptes Rendus, exxiv. (1897) pp. 831-4 (3 figs.). 
t Zool. Jahrb. (Abth. Syst.), x. (1897) pp. 56-90 (4 pis , 3 figs.). 
j Biol. Centralbl., xvii. (1897) pp. 273-82. 
§ Zool. Jahrb. (Abth. Syst.), x. (1897) pp. 135-200 (1 pi.). 
|| Quart. Journ. Micr. Sci., xxxix. (1896) pp. 219-31 (1 pi.). 
