OVUM IN THE CAPE AND NEW ZEALAND PERIPATUS. 301 



EXPLANATION OF PLATES XXIX, XXX, & XXXI, 



Illustrating Lilian Sheldon's paper on " The Maturation ot 

 the Ovum in the Cape and New Zealand Species of 

 Peripatus." 



All the figures were drawn from the sections with Zeiss's camera iucida. 

 The degree of magnification, or the powers under which they were drawn, are 

 mentioned after the description of the figures. In those which were drawn 

 under an immersion lens the details were examined under Powell and Lealand's 

 apochromatic oil immersion lens n.a. 1*40, eyepieces 10 and 20. 



Alphabetical List of Reference Letters. 



C. 0. Cavity of ovarian tubes. Fol. Follicle. Fol. Nu. Follicle nuclei. 

 G. Ep. Germinal epithelium. (?. S. Germinal spot. Q. V. Germinal vesicle. 

 /. Up. Epithelium lining ovary. Nl. Nucleolus. Nu. Nucleus. 0. Up. 

 Outer epithelium of ovary. 0. S. Egg-shell. Ov. Ovum. P. b. 1. First 

 polar body. P. b. 2. Second polar body. Fed. Peduncle attaching ovum to 

 ovary. Per. Wall of pericardium. Pron. ($. Male pronucleus. Pron. ? . 

 Female pronucleus. Sp. Spermatozoa. 



Fig. 1. — Transverse section of the ovarian tubes of Peripatus capensis 

 at the end of April, after the ova have passed into the uterus. C. 0. Cavity 

 of ovarian tube. G. Ep. Germinal epithelium. Per. Wall of pericardium. 

 Sp. Spermatozoa. Zeiss, oc. 2, obj. B. 



Fig. 2. — Section of a small portion of the wall of the ovarian tube of P. 

 capensis at the end of April, highly magnified. /. Ep. Epithelium lining 

 the cavity. 0. Ep. Outer epithelium. Zeiss, oc. 2, Reichert's J^th oil imm. 



Fig. 3. — Section of a portion of the germinal epithelium of P. capensis 

 in July. C. 0. Cavity of ovarian tube containing spermatozoa. G. S. Ger- 

 minal spot. G. V. Germinal vesicle. Ov. Ovum. Zeiss, oc. 3, obj. CC. 



Jie. 4. — Section of a portion of the germinal epithelium of P. capensis 

 in September. Letters as in Fig. 3. Zeiss, oc. 3, obj. C C. 



Fig. 5. — An ovum and its attachment, from the same ovary as Fig. 4. G. S. 

 Germinal spot. G. V. Germinal vesicle. 0. S. Egg-shell. 



Fig. 6. — Nucleus of an ovarian ovum of P. capensis shortly before its 

 disappearance, showing its crinkled outline. Greatest length of nucleus "GiS 

 mm. Nu. Nucleus. 0. S. Egg-shell. Zeiss, oc. 2, Reichert's j^gth oil imm. 



I'iG. 7. — Last stage of the nucleus in P. Balfouri before its complete 

 diappearance; Zeiss, oc. 2, Reichert's J^th oil imm. 



