ALIMENTARY CANAL IN THE BEE 551 



artificially instead of taking false steps and applying empirical 

 methods, as hitherto practised. 



One of us (E. Zarin, 1917) has already made some progress 

 towards the solution by purely chemical methods of the question 

 regarding the necessity of acidulating the winter food of bees, 

 which is of practical importance and is applied by many 

 practical bee-keepers. 



It was proved that acid (0-1 per cent, citric) produces no 

 useful action upon the inversion of cane-sugar and the ripening 

 of honey, whereas acid ' added to the food in the amount of 

 0-3 per cent, produces a depression not only in the process of 

 sugar invertion, but in all the other processes taking place in 

 the honey-stomach of the worker-bee, as well as in the hive 

 during ripening of the honey '. In the final conclusions these 

 data ' disagree with the view prevalent among bee-keepers 

 regarding the necessity of adding acid to the food '. 



At the first opportunity we shall endeavour to continue our 

 work in the direction mentioned, which is especially advan- 

 tageous, since in it deep scientific problems are conveniently 

 combined with the requirements of practical life. 



References. 



Auzinger. — " Ueber Fenneiite im Houig und den Wert ihres Nachweises 



fiir die Honigbeurteilung ", ' Ztschr. f. Untersuch. d. Nahi\- u. Genuss- 



mitt.', 1910, vol. 19, p. 70. 

 Axenfeld.^ — " Invertiii im Honig und im Insektendarm ", ' Zbl. f. Physio- 



logie ', 1903, vol. 17, p. 268. 

 Berlese, A.—' Gli Insetti ', Milano, 1909. 

 Bordas, L. — " Appareil glandulaire des Hymenopteres ", ' Ann. Sc. Nat., 



Zoologie ', ser. vii, vol. 19, 1895. 

 Chun. — " Ueber den Bau, die Entwicklung und physiologische Bedeutung 



der Rectaldriisen bei den Insekten", ' Abhandl. (Senkenbergschen Ges, 



Frankfurt ', 1876. 

 Dufour, L. — " Recherches anatomiques et physiologiques sur les Ortho- 



pteres, les Hymenopteres et les Neuropteres ", ' Mem. des Savants 



etrang. a I'Acad. des Sciences ', vol. 7, 1871. 

 Erlenmeyer und Planta. — " Ueber die Fermente in den Bienen, im Bienen- 



brod und im Pollen und iiber einige Bestandtheile des Honigs", ' Chem. 



Zbl.', 1877, p. 790. 



