154 Beekeeping 



CEnocytes. Koschevnikov ' states that the oenocytes of 

 the young adult bee have a uniform, sHghtly pigmented 

 protoplasm, while in old bees yellow granules begin to ap- 

 pear in these cells. After the winter confinement, these 

 granules are numerous and in old queens they are especially 

 abundant. According to the view of this author, oenocytes 

 are excreting cells which take up waste products of katabo- 

 lism and, after modifying them, deliver them again to the 

 blood to be carried to the Malpighian tubules. The changes 

 of age may be interpreted as due to an accumulation of these 

 products in cells which are no longer able to discharge them. 

 This failure of the oenocytes should be investigated from 

 the point of view of the term of life of the bee. In some of 

 the primitive insects the fat body is supposed to function 

 as a permanent storage for urates. 



LOCOMOTION 



Bees are able to go from place to place by means of two 

 systems of locomotor organs, the wings and the legs. Both 

 of these are attached to the thorax and the muscles of flight 

 are so well developed that they occupy almost the entire 

 space in the thorax. 



The wings (Fig. 80) are membranous structures with a 

 definite framework of veins attached to the sides of the 

 thorax. As previously explained (p. 99) they are not 

 primary embryonic appendages, but are secondary out- 

 growths from the second and third thoracic segments. The 

 details of the venation of the wings need not be considered 

 at length. This has been investigated in a careful manner 

 by Comstock and Needham ^ and the designations used in 

 Fig. 80 are those decided upon by these authors after a 

 study of the comparative venation of the various orders of 

 insects. The symbols are explained in the appendix. The 



1 Koschevnikov, G. A., 1900. Ueber den Fettkorper und die CEnocyten 

 der Honigbiene (,Apis mellifera L.). Zool. Anz., XXIII, pp. 337-353. 



2 Comstock, J. H., and Needham, J. G., 1898-99. The wings of insects. 

 Am. Nat., XXXII and XXXIII: Reprinted, Ithaca, N. Y. 



