184 PROF. W. H. JACKSON ON THE 



aperture, into which the pupal cuticle, cu., is prolonged. A small portion of the cuticle lies 

 detached in the lumen of the oviduct. 



55 g. The eighteenth section of the series. The sebaceous region, #/., is more clearly marked. The 

 azygos oviduct, od.', is closed below, but continuous with the hypodermis, /*. cu., the pupal 

 cuticle. 



55 h. The twentieth section of the series. The vesicle region of the sebaceous glands, v.gl, is 

 shown dorsally ; below it are the cut ends of the two sebaceous glands, gl., which are turned 

 ventrally. h, and cu., as before. 



55 i. The twenty-second section of the series. The sebaceous glands, #/., are so much curved upon 

 themselves that they are cut through twice over. The next section passes through the apex of 

 the curve. Compare fig. 38, PI. XVII., which shows what the external appearance corre- 

 sponding to the sections must be alike, h, and cu., as before. 



Plate XIX. 



With the exception of figs. 59 and 64, all the figures on this Plate are drawn to the same scale as the 

 figures on the preceding Plate, viz. under obj. B, oc. 2, Zeiss, draw-tube in. 



Fig. 56. Transverse section through the anterior end of the azygos oviduct. Three sections behind 

 fig. 58. od.', the azygos oviduct. It is solid and composed of cells cut obliquely, with a small 

 amount of transparent intercellular substance closely resembling fig. 47, PI. XVII., which is, 

 however, more highly magnified. It is seen to be continuous with the hypodermis, h, and 

 probably represents a solid invagination of that layer of cells, cu., the delicate pupal cuticle. 

 cu.' , the larval cuticle. 

 Figs. 57 a to 57 d. Transverse sections of the azygos oviduct from a pupa one day old. 



57 a. Section just behind the spot where the solid azygos oviduct, od.', is joined by the paired 

 oviducts. Note the extreme thinness of the hypodermis, h, beneath it, a feature seen also in 

 the next section, and showing probably that the hypodermis cells have undergone transverse 

 fission. 

 57 b. The next succeeding section, still solid. 

 57 c. The next section with a lumen ; its ventral wall is thin. 



57 d. The next section. The lumen is larger ; the hypodermis, h, is cut obliquely and therefore 

 looks abnormally thick, cu., the pupal cuticle. It is naturally V-shaped, as the portion cut 

 through is the commencement of the median furrow in the eighth segment, shown fig. 7, 

 PI. XV. 

 Fig. 58. Surface view of the junction between the paired oviducts, od., and the azygos oviduct, od.' 

 The plane of the section is nearly parallel to the surface. The hypodermis cells are cut trans- 

 versely. The section is taken from a quiescent caterpillar, the same specimen from which 

 fig. 56 is taken. 

 Fig. 59. Transverse section of the right paired oviduct taken from the same specimen as fig. 55 in the 

 preceding Plate. It is solid and there is a single row of superficially placed nuclei. Obj. D, 

 oc. 2, Zeiss, draw-tube in. 

 Fig. 60. Longitudinal section of the right paired oviduct from a pupa two days old. The drawing is 

 taken close to the ventral end, just where the lumen ends. The union with the azygos oviduct 

 in this specimen is solid. 

 Pig. 61. A similar section from a three days old pupa. 



Fig. 62. A transverse section from a pupa of the same age as the last, showing the junction between the 

 lumina of one of the paired oviducts, od., and the azygos oviduct, od.' 



