ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
121 
Italian Coccidse of Fruit-Trees.* * * § — Prof. A. Berlese deserves to be 
congratulated on bis memoirs dealing with Coccid insects living on 
fruit-trees in Italy. These insects are interesting in their structure and 
life-history; they are not less interesting to the practical man whose 
orchards they infest. Both aspects receive due consideration from 
Prof. Berlese, who furnishes on the one hand a most detailed morpho- 
logical account, and on the other hand what we may call a system of 
practical lore. As will be seen from our reference the abundance of 
illustrations is a feature of these memoirs. The first deals with the 
genus Dactylopius, with two species, D. citri Bisso and D. longispinus 
Targ. Tozz. The second deals with the genus Lecanium, with two 
species, L. hesperidum Linne, and L. olese Bernard. The third deals 
with six species of Diaspitidae — Mytilaspis fulva Targ. Tozz., M. pomorum 
Bouche, Parlcitoria Zizyphi Lucas, Aspidiotus dimonii Signorot, A. Ficus 
Kiley, and Aonidiella Aurantii Mask. 
Buccal Glands of Larval Trichoptera.-j* — M. Maurice Henseval finds 
that the larvae of Trichoptera may exhibit at the base of their masticu- 
latory organs one or two pairs of glands with intracellular canals. They 
were absent in the Phryganid larvae examined, but these have “ Gilson’s 
glands ” much developed. The organs in question probably represent 
the coxal glands of the anterior metameres. 
How Flowers attract Insects.^ — Pursuing his researches on this 
subject, Prof. F. Plateau has come to a different conclusion from that of 
Darwin, who held that it is chiefly the bright colour of the corolla that 
attracts insects to flowers for the purpose of pollination. His experiments 
were made chiefly on Dahlia variabilis (single), Lobelia Erinus , (Eno - 
thera biennis , Delphinium Ajacis , Ipomsea purpurea, Centaurea Cyanus, and 
Digitalis purpurea. In the case of the Dahlia and other Composite the 
removal of the conspicuous ray-flowers had very little effect in diminishing 
the number of insects which visited them ; these cannot therefore play the 
part of signals or banners attributed to them by Darwin and others. Similar 
results were obtained by removing the conspicuous part of the corolla in 
the other flowers which were subjected to observation. Covering up of 
the flower by leaves also had but little hindering effect on the visits of 
insects. The author concludes that insects are attracted to flowers 
chiefly by some other sense than that of sight, probably by that of 
smell. 
Prof. Plateau further states as the result of experiments on these 
points, that insects visit indifferently flowers of different colours belong- 
ing to the same species ; § that they light without hesitation on flowers 
habitually neglected when these are artificially supplied with honey ; 
and that they at once cease their visits to the customary flow'ers when 
the nectary has been removed from them. 
* Part I. ex Piivista Patologia Vegetale, ii. (1893) 106 pp., 3 pis. and 45 figs. ; 
Part II. ex op. cit., iii. (1894) 201 pp., 12 pis. ; Part III. ex op. cit., iv. and v. (1896) 
477 pp., 12 pis. and 200 figs. f La Cellule, xii. (1897) pp. 7-15 (1 pi.). 
J Bull. Acad. R. Sci. Belgique, xxx. (1895) pp. 466-S8; xxxii. (1896) pp. 505-34 
(1 pi.) ; xxxiii. (1897) pp. 17-41. Cf. this Journal, 1896, p. 305. 
§ Similar results were obtained by Mr. A. W. Bennett (Journ. Linn. Soc. ; Zool., 
xvii. (1883) p. 175). 
