ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
411 
Britain and America, and finds that the American eggs are more variable 
in ratio of breadth to length, and in colour. “ Granting that the 
sparrow, since its introduction (1850), has been comparatively free from 
the action of natural selection, we may conclude that the predicted 
results of Panmixia have been realised.” The author discusses this 
conclusion. He suggests that “ English and American birds should be 
placed in some third locality which combines equally or eliminates the 
prejudicial environmental conditions of the two countries. Then, and 
not until then, shall we know to what extent the ontogenic variations 
in either country have really become phylogenic.” 
Variability in Fishes.* — Dr. G. Duncker has been engaged in 
investigating the variability of Pleuronectes flesns and Siphonostoma 
typhle L., and makes a short note on some of his results that have a 
local faunistic interest. The flounders of Plymouth, when compared 
with those of the Baltic and the south-eastern parts of the North Sea, 
form a distinct race. The characteristics of this race are: — (1) a high 
number of fin-rays in the dorsal and anal fin (average, dorsal 61—62, 
anal 43—44) ; (2) almost entirely smooth squamation on the blind side. 
In both respects it is similar to the variety PI. italicus Gunther, of the 
Mediterranean. There are adequate reasons for separating Syngnathus 
rostellatus Nils., and S. acus L., both occurring at Plymouth. 
Polydactylism and Syndactylism in Mammals. t — Dr. G. Tornier 
describes some cases of polydactylism in pig and deer. He agrees with 
Zander that the efficient cause is to be found in the pressure of the 
amnion-folds. As the result there is atrophy of certain parts and 
“ super-regeneration ” of others. Often, but not always, the results appear 
as if there had been a fusion of parts of a right foot with a normal left, 
or vice versa ; but it seems impossible to make any generalisation. In 
many cases, too, polydactylism is associated with syndactylism which is 
the result of some inhibitory action during development, e.g. of pressure 
from the amnion-folds. 
Polydactylism in Swine.* — Herr J. Werner notes three cases of this, 
observed during eight weeks at the city slaughter-house in Leipzig. 
All concerned the fore-feet, and in one case the extra digit exceeded the 
normal posterior size. He also notes a case in which the soles of the 
two median digits had coalesced. 
Intelligence of Fishes.§ — Prof. W. C. McIntosh has a very inter- 
esting short paper, which we may be permitted to wish that he would 
extend, on the memory of fishes. Some of the cases given demand a 
somewhat wider title. He speaks of £ the behaviour of a large grey 
skate in its endeavour to escape over a trawl-beam more than 50 feet 
long which had been arrested in its rise — just above the surface of the 
sea — by a temporary block in the machinery. The dexterity with which 
it skimmed to and fro along the beam to find where it dipped suffi- 
ciently during the movements of the ship to enable it to glide over was 
a study. ... If those who have given a green cod of six or eight 
* Journ. Mar. Biol. Ass., v. (1898) pp. 172-5. 
f SB. Ges. Nat. Freunde Berlin, 1897, pp. 64-8. t Tom. cit., pp. 47-8. 
§ Journ. Mental Sei., April 1898, 4 pp. 
2 F 
1898 
