150 F. H. STEWART. 



Fig. 29. — Transverse section, testicular region, x 350. Stain : ITfema- 

 toxylin, oosin. 



Fig. 30. — Transverse section tlirongli vas deferens at its opening into 

 seminal vesicle ; portion of wall of latter sliown. x 3.50. Stain : II?cnia- 

 toxylin, eosin. 



Fig. 31. — Portion of transverse section, ductus ejaoulatorius. X 350. 

 Stain: IlaiUiatoxylin, eosin. 



Ascaris capsnlaria. 



Fig. 32. — Transverse section, showing ventral gland, x 80. Stain : 

 Hsematoxjlin, eosin. 



Fig. 32 «. — Transverse section through ventral gland, anterior portion. 

 X 350. Stain: Hseniatoxylin, eosin. 



Fig. 33. — Oblique section through duct of ventral gland. X 350. Stain : 

 Hsematoxjlin, eosin. 



PLATE 9. 



Diagrams illustrating the development of the excretory apparatus in 

 Nematodes. 



(Figs. 37-40 are based on the descriptions given by Jagerskiold [0]). 



Fig. 34. — Skin-gland of lateral line. 



Fig. 35. — Ventral gland of eg., Oncholaimus vulgaris. 



Fig. 36. — Ventral gland of Ascaris capsularia. 



Fig. 37. — Excretory organ of A. decipiens. 



Fig. 38. — Excretory organ of A. rotundata. 



Fig. 39. — Excretory organ of A. elavata. 



Fig. 40. — Excretory organ of A. megalocephala. 



