MOKPIIOLOGY OF THE LEPIDOPTEEA. 169 



of the azygos oviduct. It grows in length antero-posteriorly. Its anterior end becomes 

 swollen and develops into the bursa copulatrix ; its posterior end becomes elongated 

 and pointed, and develops into the receptaculum seminis. 



The rudiment of the bursa copulatrix gives origin to the terminal vesicular portion of 

 the organ and to that portion of the bursal duct which is dorsal to the point of entrance 

 of the seminal canal. The bursa and its duct at first open into the dorsal aspect of the 

 azygos oviduct ; they then shift to its left side and are continuous with the tubular 

 portion of the oviduct leading to the bursal aperture, which becomes the portion of the 

 bursal duct ventral to the point of entrance of the seminal canal. Finally, the lateral 

 connection between the bursal duct and the azygos oviduct becomes tubular and forms 

 the seminal canal. 



The rudiment of the receptaculum seminis is at first bent down upon itself to the left 

 side ; it increases rapidly in length and straightens out. It has a transitory pyriform 

 vesicle appended to it. Later on it is differentiated into the three sections recognizable 

 in the imaa'O. 



(6) The two sebaceous glands of the imago, their vesicles and common duct leading to 

 the azygos oviduct, are derived from the median dorsal portion of the paired posterior 

 vesicles invaginated from the hypodermis of the ninth sternal region, whilst the 

 common or basal ventral portion of the same vesicles becomes the extreme posterior end 

 of the azygos oviduct. 



The anterior end of the dorsal portion retains an aperture into the azygos oviduct and 

 becomes subsequently the tubular duct and the vesicular dilatations of the glands. 



The posterior end of the dorsal portion grows out into two tubes, a right and left, the 

 sebaceous glands proper. They are at first curved upon themselves and parallel to one 

 another. As they lengthen they diverge and turn forward. 



(7) The odoriferous glands of Vanessa originate as separate tubular ingrowths, a right 

 and a left, from the hypodermis just in front of the oviducal aperture. Later on they 

 acquire a common vestibule. 



(8) It has been shown incidentally that the caterpillar and the pupa possess ten 

 abdominal somites, corroborating Packard's statement as to the caterpillar. 



(9) The terminal papilla of the abdomen of the imago is formed by the ingrowth of 

 two folds of hypodermis, a right and left, inclosing a small portion only of the area of 

 the tenth somite. Accordingly it does not represent a ninth somite, as is generally held ; 

 the whole ninth somite and the rest of the tenth somite of the pupa are not clearly 

 marked off from the eighth somite of the imago. The cremaster disappears completelv 

 in the course of pupal life. The apparent eighth, tergum of the imago probablv 

 represents the eighth and ninth pupal terga, and the tenth, if any portion of it is 

 persistent. The pleural region of the ninth pupal somite and of the tenth, so far as it 

 exists, is represented by the soft membrane lying behind the ridge extending dorsally 

 from the eighth sternum of the imago (PL XVI. fig. 25 x ). As the bursal aperture 

 lies near the centre of the eighth sternum, this region may possibly include in the imago 

 a portion of the ninth sternal region as well. The softer integument behind connecting 

 it to the base of the terminal papilla would in that case coincide with a portion of the 



2G* 



