ZOOLOGY AND BOTANY, MICROSCOPY. ETC. 181 



eggs laid by unfertilised queens or by workers do invariably give rise 

 to drones, but maintains that such drones snow well-marked differences 

 from those which appear in a colony with a healthy fertilised queen at 

 its head ; he considers that his results prove that such a queen can only 

 lay fertilised eggs, and tbat it is the influence of tbe workers which 

 determines the future development of the eggs. He believes, further,, 

 that the workers, in crawling over the brood-cells as soon as eggs have 

 been laid in them, pour out a secretion which penetrates the chorion 

 and reacbes the egg. More than this, the wax which makes the cells is 

 kneaded in the mouth, and during this process be believes tbat it is 

 impregnated from the " salivary glands " with the secretion character- 

 istic of drone, of worker, or of queen-cells. According to the paiticular 

 nature of the secretion, the type of the cell is determined, and the 

 presence of the particular secretion in the walls of tbe cell determines 

 the nature of the additional secretion poured into the cell when tbe egg 

 is laid. The question as to whether each worker is capable of pro- 

 ducing tbe three types of secretion, or whether three kinds of worker 

 exist, is left undetermined. The author believes that this theory will 

 explain in a satisfactory way all tbe anomalies of bee-development. 

 Further, be compares tbe secretion of fluid from the " salivary glands " 

 in the workers to a sexual act, and believes that it produces in them the 

 same emotions as those usually associated with sexual union. 



In another paper,* the author replies to Petrunkewitsch's re-assertion 

 of the traditional position in regard to drone eggs. Petrunkewitsch 

 believes that all eggs laid by the queen in drone-cells are unfertilised, 

 basing his belief largely on the fact that no sperm and no centrosome 

 rays have been observed in such eggs. Dickel, however, replies that 

 as such eggs do in some cases give rise to worker bees, Petruukewitsch 

 proves too much for his own case. On other grounds also Dickel thinka 

 the microscopic evidence unreliable. 



Studies on Galls.f — Manuel Fernandez de Gatta discusses the galls 

 of Salicacese (due to Nematus versicolor, N. gallicola, N. vallisnierii, &c.) ; 

 of Ulmaceae (due to Schizoneura lanigera, Sch. ulmi, &c.) ; of Papilionacese 

 (due to a species of Diastrophus and to Bacteria) ; of Terebinthaceae (due 

 to Pemphigus cornicularius, P. utricularius, &c.) ; of Kosaceae (due to 

 species of Ehodites, &c.) ; of Oleacese (due to Bacteria) ; and so on. 



Dragon flies of Illinois.:}:— Prof. J. G. Needham and Mr. C. A. Hart 

 give an account of the Petaluridae, ^schnidae, and Gomphidse of Illinois 

 (twenty-eight species), and it is noteworthy that they describe the 

 nymphs of twenty-four species (six for the first time). The authors 

 give an interesting account of the habitats and food-relations, and useful 

 diagnostic tables. 



New Collembola.§— Carl Borner describes a number of new species 

 of Collembola, and discusses tome points connected with the nomencla- 

 ture of the previously known species. One of the new species falls into 

 a new genus— Micranurida, which resembles Anurida in general form, 



* Tom. cit., pp. 20-7. 



t Boll. Soc. Eapan. Hist. Nat., i. No. 10 (1901) pp. 385-402. 

 X Bull. Illinois State Lab. Nat. Hist,, vi. (1901) pp. 1-94 (1 pi.). 

 § Zool. Anzeig., xxiv. (1901) pp. 096-712 (10 figs.). 



