On the reproductive system of Planaria simplissima. 465 



Plate 31. 



Fig. 1. A reconstruction from sections of the reproductive system 

 of Planaria simplissima seen from the dorsal aspect. The outline of 

 the body is shown. The branches of the yolk-glands are omitted, but 

 their connection with the oviducts at irregular intervals is indicated. 

 B. and L. ^/g Obj., 2 In. eye-piece. 



Fig. 2. Section through a testicular follicle with which are con- 

 nected two smaller follicles. The section is taken in the longitudinal 

 axis of the animal and shows the testicular canal leading into the vas 

 deferens. The whole is represented in its relation to the dorsal body 

 surface and the gut lobes. B. and L. ^/g Obj., 2 In. eye-piece. 



Fig. 3. Part of a transverse vertical section through the region 

 of the penis and uterus (see Fig. 1 or Fig. 8). The figure represents 

 a sector of the penis and atrium with the uterus above in their relation 

 to the dorsal surface of the body. B. and L. ^/^g Obj., 2 In. eye- 

 piece. 



Fig. 4. Transverse section through an ovary and oviduct near 

 their union, showing cavities in the ovary continuous with that of the 

 oviduct. The relation to the ventral surface of the body is shown. 

 B. and L. i/^j Obj., 1 In. eye-piece. 



Fig. 5. Transverse section through the vas deferens showing 

 spermatozoa in the lumen. B. and L. ^/j^g Obj., 1 In. eye-piece. 



Fig. 6. Transverse section through opiduct and vas deferens 

 showing spermatozoa in lumen of each and nuclei of the parenchyma 

 surrounding the oviduct. B. and L. ^/^^ Obj., 1 In. eye-piece. 



Fig. 7. A vertical longitudinal section near the line of one Vas 

 deferens (see Fig. 1) in which portions of the testicular canals from 

 four testes are seen. The position of the fifth follicle with its testi- 

 cular canal leading to the seminal vesicle and the course of the Vas 

 deferens are indicated by the dotted outlines. B. and L. y g Obj., 

 2 In. eye-piece. 



Fig. 8. The left ^/2 of the productive system in Planaria simplissima 

 from a lateral aspect. Reconstructed from the series from which Fig. 7 is 

 taken. The outline'of the pharynx is shown and the dorsal and ventral sur- 

 faces of the body as they appear along the mid-line. The yolk-glands 

 are shown as in Fig. 1. B. and L. ^/g Obj., 2 In. eye-piece. 



Plate 32. 



Fig. 9. A horizontal section through an ovary and oviduct where 

 they unite. The irregular shape of the ovary is shown and a portion 

 of it some distance away in the parenchyma with no discoverable con- 

 nection. The connection of the yolk glands to the oviduct is also 

 shown. B. and L. i/^^ Obj., 2 In. eye-piece. 



Fig. 10. Portion of a transverse section showing a testicular fol- 

 licle with its testicular canal passing to the vas deferens. Repre- 



