1919] Ruckes: Male Genital System in Lepidoptera 205 



C. THE ACCESSORY GLANDS. 



In the accessory glands, the cells do not become con- 

 spicuously glandular, as might be expected from the terminology 

 of these organs. 



The cells remain columnar in character and do not form 

 pseudonidi. They do not become vacuolate, in the same sense 

 that the cells of the vas deferens become vacuolate. The 

 cytoplasm presents a very spongy appearance, that is present 

 in very young cells of the glands. At first this condition might 

 easily be taken for a general vacuolization. Comparisons with 

 other types of cells show that it is quite different, however. 

 Many authors believe that there is a secretion of these organs, 

 and that the secretion causes the formation of spermatophores. 

 This may be true. Secretion is not as evident as in the cells of 

 the glandular part of the vas deferens, and proceeds in a differ- 

 ent manner. 



The accessory glands differ from the organs previously 

 discussed, in the possession of a single longitudinal layer of 

 muscle. This i-n early stages of the development of the repro- 

 ductive system may be continuous with the muscle of the upper 

 end of the ejaculatory duct. This has not been definitely 

 determined. 



Koschevnikow (1891) found three layers of muscle in the 

 glands of Apis; an inner longitudinal layer which may not 

 extend the entire length of the tubes, a central circular and an 

 outer longitudinal. 



In some insects the accessory glands may actually be 

 ectodermal in origin. Many authors do not believe so, however. 

 If they were ectodermal, there would be a tendency toward the 

 formation of an intima, which, as far as has been determined, 

 does not exist in them. 



D. THE EJACULATORY DUCT. 



As stated previously, the ejaculatory duct consists of two 

 parts, at least it is so considered by several authors, prominent 

 among whom is Schroeder. The upper part is divided into two 

 tubes, the ductus ejaculatorius duplex (of Schroeder), which 

 are short and connect at their cephalic end with the seminal 

 vesicles. These tubes are probably simply caudal prolonga- 



