120 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
circulans-gall due to Andricus circulans in whose life-history hetero- 
genesis is also probable, though not exactly demonstrated. 
Of galls in general the author notes that the higher the final differen- 
tiation, the younger must be the initial cells of the vegetable tissue 
which are affected by the animal excreta. All Oynipid-galls arise from 
a group of vegetable cells, 250-2000 in the case of Cynips calicis. Any 
theory of the formation of the gall must keep in view the diffusion of the 
irritant substance through a cell-complex. The facts seem to Beijerinck 
to show that variation is a function of multicellular relations in the case 
of most galls. It seems to us that most biologists would regard galls as 
phenomena of modification rather than of variation, but the author is no 
doubt right in emphasising their importance in connection with the 
general problems of organic growth and organic change. 
Coloration of Scales in Beetles.* * * § — Sig. A. Garbasso has been in- 
vestigating the physical coloration of certain insects, but has, he notes, 
been in part forestalled by Walter’s book on Schillerfarben. In this 
paper he confines himself to a description of the structure of the scales 
in the Curculionid Entimus imperialis, and to showing that its brilliant 
colours are due to phenomena of interference. 
Life-History of Dendroetonus micans.j — MM. A. Menegaux and 
J. Cochon call attention to the biology of this largest of xylophagous 
insects, which was unknown fifty years ago, and was long thought to be 
innocuous. The great danger connected with it is that it never attacks 
dead trees or trunks, but always healthy trees ; a tree weakened by it 
may be subsequently attacked by other xylophagous forms, such as 
Bostrichus. 
Abdomen of Scolytidse.i — Dr. C. Verlioeff has studied the abdomen 
of Scolytidee, with special reference to the work of Prof. C. Lindemann 
(1875) on the same subject, and with general reference to the morphology 
of the insect-abdomen. 
As the tersest possible summary of his results fills three pages, we 
cannot do more than refer to the general tenor of Verhoeff’s paper. 
Bees Intoxicated with Honey.§ — Mr. J. L. Williams describes the 
remarkable effect produced on humble-bees by the honey of certain 
flowers with dense capitulate inflorescence belonging to the Composite 
and Dipsacaceae : — Centaur ea nigra , C. scabiosa, Car duus lanceolatus , C. 
nutans, and Scabiosa succisa. The species chiefly observed were neuters 
of Bombus lapidarius. After extracting the honey, the insect suddenly 
turned on its side and moved the second pair of legs convulsively in the 
air ; some even turned on their backs and rolled on the flowers. After 
a time a few tried to fly away, but their wings seemed powerless to raise 
them into the air, and they fell on the ground instead. As a rule, when 
driven away, they were eager to return. During this proceeding the 
bees invariably became covered with pollen, and the author suggests that 
the habit may be useful to the flower in promoting cross-pollination. 
* Mem. R. Accad. Sci. Torino, xlvi. (1896) pp. 179-86 (1 pi.). 
1 1 Comptes Rendus, exxiv. (1897) pp. 206-9. 
X Arch. Naturges., lxii. (1896) pp. 109-44 (2 pis.). 
§ Journ. Bot., xxxv. (1897) pp. 8-11. 
