20 SUMMARY OF CURRENT RESEARCHES RELATING TO 



four appendicular segments : (1) the mandibular ; (2) the endolabial - 

 (3) the maxillary ; and (4) the ectolabial (" labial " of most authors). 



Structure of the Insect Ovary.* — Heinrich Ritter von Wielowieyski 

 has investigated the structure of the ovary in various types of insects. 

 The essential constituents are : the terminal filament, the tunica 

 propria, the follicular epithelium, and the germ-cells, and the author 

 discusses these in detail. The nutrition of the ova in Orthoptera 

 (except Forficula) and in the flea is either direct through the tunica 

 propria or by help of the follicular epithelium from the blood (panoistic 

 ovaries). In all other groups there is a differentiation of the germinal 

 material into oocytes and nutritive-cells. The nutritive-cells are 

 originally germ-cells or their direct derivatives. Follicle-cells never 

 become nutritive-cells. The nuclei of the nutritive-cells behave like 

 those of most gland-cells. 



Bees and Flowers.t — J. Wery has made experiments with flowers 

 from which the corolla was removed and others which were left un- 

 injured. The position was changed from time to time, and the visits of 

 the bees were counted. In June the uninjured flowers were visited by 

 107 insects, of which 72 were bees ; the flowers without corolla, but still 

 conspicuous, were visited by 79 insects, of which 28 were bees. Similar 

 experiments had similar results. A glass vessel with honey was left 

 unvisited ; artificial flowers proved as attractive as the real flowers. 

 The author concludes that the form and colour of the flowers are 

 indisputably more potent in attracting bees than the pollen, nectar, or 

 fragrance. 



Wax-Glands of Bees.J — L. Dreyling points out that in Bombus the 

 wax-glands are formed dorsally and ventrally, and that nearly the whole 

 of the hypodermis of the segments shares in the secretion. In Melipona 

 and Trigona the secretion is restricted to the dorsal surface, in hive-bees 

 to the ventral surface. In various respects, as regards the wax-glands, 

 the humble-bees are intermediate between the solitary and the social 

 Apidae. 



Wax-forming Organs in Social Bees.§ — L. Dreyling gives a full 

 account of the regions bearing these organs in the honey-bee and in 

 Meliponidge. In the workers of the honey-bee wax is secreted by 

 specially developed skin-glands on the last four ventral plates of the 

 abdomen. These glands are recognisable even in the pupa stage ; in the 

 fully developed bee, after their maximum of development is reached, 

 they gradually degenerate with increasing age. The Meliponidae have 

 the wax-secreting glands on the dorsal side of the abdomen, otherwise 

 they are similar to those of the honey-bee. The Trigonse likewise 

 secrete wax on the dorsal side of the abdomen in segments 2-6. On 

 the same segments wax occurs in the humble-bees also, where, however, 

 wax-glands are developed ventrally as well as dorsally. 



* Arbeit. Zool. Inst. Univ. Wien, xvi. (1905) pp. 1-62 (3 pis.), 

 t Bull. Acad. Roy. Belgique (1904) 53 pp. See also Biol. Centralbl, xxv. (1905) 

 pp. 270-1. \ Zool. Anzeig., xxix. (1905) pp. 563-73 (6 figs.). 



§ Zool. Jahrb., xxii. (1905) pp. 289-330 (2 pis.). 



