112 HYMENOPTEKA. 



wax u is produced by an exudation from the thin membranes 

 which connect the different parts of the legs. Moreover, many 

 other Insects (Coccidce and Aphidce, Plata, etc.) have secretory 

 products which transude through the skin without the existence 

 of any special glandular apparatus, and which are hardened by 

 the air like wax. These products are usually whitish, pulver- 

 ulent, filamentous, or flocculent substances, which catch upon 

 the surface of bodies." He also states that there are no such 

 glands (as are supposed by some to secrete this substance) in the 

 "bee-workers; but if certain Andrenidae are examined, there 

 will be found, on each side of their posterior tibiae, a small pyri- 

 form follicle with an excretory duct, and which secretes an oily 

 substance." Gerstrecker states that the wax is produced on 

 the under side of the abdominal segments. It is formed by 

 chemical changes in the food during the process of nutrition. 



The honey is elaborated by an unknown chemical process, 

 from the food contained in the proventriculus, or crop, and 

 which is regurgitated into the honey-cells. 



The ovaries consist of many-chambered, four, six, or a hun- 

 dred, short tubes. "The receptacula seminis is nearly always 

 simple, round or ovoid, and necked, and is prolonged into a 

 usually short seminal duct." The glandula apx>endicularis con- 

 sists of a bifurcate tube which opens into the ductus seminalis, 

 and only rarely into the capsula seminalis itself. 



In the Tenthredinidce , "this apparatus is formed on a 

 different type. ; the seminal vesicle is a simple diverticulum of 

 the vagina, and more or less distinct from it, besides it is defi- 

 cient in the accessory gland. The copnlatory pouch is absent in 

 all the Hymenoptera, as are also the sebaceous glands with those 

 females which have a sting and a poison gland," while in other 

 insects the sebaceous glands are present, and it would be nat- 

 urally inferred, therefore, that the two are homologous, but 

 modified for diverse functions. 



The two testes of the male are "composed of long follicles, 

 fasciculate and surrounded, together with a portion of the 

 torose deferent canal, by a common envelope ; but more com- 

 monly the two testes are contained in a capsule situated on the 

 median line of the body." (Siebold.) 



The eggs are usually long, cylindrical, and slightly curved in 



