MOEPHOLOGY OF THE LEPIDOPTERA. 181 



turned to the left side ; whilst the sebaceous glands, gl., are no longer parallel to one another, 

 but are still directed backwards. 



Fig. 41. Lateral view of the same specimen from the right side. The duct of the bursa, i.e., has become 

 slightly apparent ; there is still a slight hook at the free extremity of the receptaculum, r.s. ; 

 the sebaceous gland, gl., is much longer, strongly bent upon itself, and the vesicle from which 

 it springs is more pronounced. The azygos oviduct, od'., is well seen ; it is vertically swollen 

 beneath the base of the receptaculum, r.s., and this is the region where the bursal duct will be 

 specialized. Behind the swelling in question it is seen to be arched, i. e. it is completely 

 detached from the hypodermis between its bursal and oviducal openings. It ends abruptly 

 beneath the vesicle of the sebaceous gland. 



Fig. 42. View from above, taken from a pupa three days old. The bursa, b.c, is now a stalked vesicle ; 

 the vesicle is the bursa itself, the stalk that section of its duct which is dorsal to the point of 

 entrance of the seminal canal. The receptaculum, r.s., is elongated and entirely straightened 

 out ; its base of attachment to the azygos oviduct is behind and to the left of the base of the 

 bursal duct, od., the paired oviducts, and od.', the azygos oviduct, p.od.' , the section of the 

 azygos oviduct which is extending backwards behind the sebaceous vesicles ; it is only just 

 visible in this view from above. gl., the sebaceous glands, which now diverge from one 

 another, but are directed backwards. Note the want of symmetry between the two glands, 

 and the well-marked vesicles from which they spring. 



Fig. 43. Lateral view of the same specimen from the right side. The two paired oviducts, od., come 

 into sight for the first time in this aspect. The bursa, b.c, and the dorsal section of its duct 

 are well seen ; the receptaculum, r.s., is quite straight ; the vesicle, v.gl., of the sebaceous 

 gland, gl., is of large size. The ventral section of the future bursal duct, d.b.c, is now a 

 vertically elongate tube, but it is in direct continuity with the azygos oviduct, p.od.' , the 

 posterior section of the azygos oviduct behind the sebaceous vesicles ; it leads to the oviducal 

 opening, which is now distinctly shifting backwards. Compare it in fig. 41. 



Fig. 44. View from above, taken from a pupa/ow days old. The bursa, b.c, is now distinctly on the 

 left side of the azygos oviduct ; it is dilated apically, but is not so sharply marked off from its 

 stalk as in fig. 42. ov., the four ovarioles of the right side ; od., the paired oviducts, which are 

 much enlarged ; od.', the azygos oviduct ; r.s., the receptaculum, now directed forwards; gl., 

 the sebaceous glands, which are more slender and also turned forwards ; v.gl., their vesicles, 

 which are better marked off ; and d.v.gl., the common duct leading from the vesicles to the 

 azygos oviduct, p.od.', the much elongated section of the azygos oviduct posterior to the 

 entrance of the common duct of the sebaceous glands. 



Fig. 45. A front view or elevation from the same specimen, showing, od., the paired oviducts, od.', the 

 azygos oviduct, d.b.c.', the section of the bursal duct dorsal to the azygos oviduct, and d.b.c., 

 the section ventral to it. It will be observed how completely these structures are placed to 

 the left side of the azygos oviduct, and how much elongated is the ventral section of the bursal 

 duct, x, the line points to the region which will differentiate into the seminal canal. The 

 change is already indicated. 



Fig. 46. Vertical view, taken from a pupa between five and six days old. od., the paired oviducts 

 greatly increased in diameter ; od.', the azygos oviduct, now a tube of the same diameter 

 throughout, d.b.c.', the dorsal section of the bursal duct differentiated from the stalk of the 

 bursa itself; d.b.c, the ventral section of the same duct differentiated by growth from the 

 azygos oviduct ; s.c, the seminal canal or tubular connection between the bursal duct and the 

 azygos oviduct ; r.s., the basal portion of the receptaculum seminis, removed by a slight space 

 from the point where the seminal canal enters the azygos oviduct. 



Fig. 47. Horizontal section of hypodermis from the seventh segment of a female caterpillar on the 

 point of pupation. It shows the cells with their nuclei in transverse section and a small 



