OVUM IN THE CAPE AND NEW ZEALAND PERIPATUS. 27 
EXPLANATION OF PLATES I, II, & III, 
Illustrating Lilian Sheldon’s paper on ‘‘ The Maturation of 
the Ovum in the Cape and New Zealand Species of 
Peripatus.” 
All the figures were drawn from the sections with Zeiss’s camera lucida. 
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 Sealand’s 
apochromatic oil immersion lens n.a, 1°40, eyepieces 10 and 20. 
Alphabetical List of Reference Letters. 
C.O. Cavity of ovarian tubes. ol. Follicle. Fol. Nw. Follicle nuclei. 
G. Hp. Germinal epithelium. G.§. Germinal spot. G. 7. Germinal vesicle. 
I. Ep. Epithelium lining ovary. M/. Nucleolus. Nw. Nucleus. 0. &. 
Outer epithelium of ovary. O.8. Egg-shell. Ov. Ovum. P. 6.1. First 
polar body. P. 4.2. Second polar body. Ped. Peduncle attaching ovum to 
ovary. Per. Wall of pericardium. Pro. g. Male pronucleus. Pron. 2. 
Female pronucleus. Sp. Spermatozoa. 
Fic. 1.—Transverse section of the ovarian tubes of Peripatus capensis 
at the end of April, after the ova have passed into the uterus. C. O. Cavity 
of ovarian tube. G. Hp. Germinal epithelium. Per. Wall of pericardium. 
Sp. Spermatozoa. Zeiss, oc. 2, obj. B. 
Fic. 2.—Section of a small portion of the wall of the ovarian tube of P. 
capensis at the endof April, highly magnified. J. Hp. Epithelium lining 
the cavity. O. Hp. Outer epithelium. Zeiss, oc. 2, Reichert’s th oil imm. 
Fic. 3.—Section of a portion of the germinal epithelium of P. capensis 
in July. C. O. Cavity of ovarian tube containing spermatozoa. G.S. Ger- 
minal spot. G.V. Germinal vesicle. Ov. Ovum. Zeiss, oc. 3, obj. CC. 
Fic. 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. 
Fic. 5.—An ovum and its attachment, from the same ovary as Fig. 4. G. 8. 
Germinal spot. G.V. Germinal vesicle, O. 8. Egg-shell. 
Fic. 6.—Nucleus of an ovarian ovum of P. capensis shortly before its 
disappearance, showing its crinkled outline. Greatest length of nucleus ‘045 
mm. Wz. Nucleus. 0.8. Egg-shell. Zeiss, oc. 2, Reichert’s 2-th oil imm. 
Fic. 7.—Last stage of the nucleus in P. Balfouri before its complete 
diappearance. Zeiss, oc. 2, Reichert’s 3,th oil imm. 
