154 
Beekeeping 
oenocytes. Koschevnikov 1 states that the cenoeytes of 
the young adult bee have a uniform, slightly 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 2 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 (Enocyten 
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. 
