[355] Loc. cit. p. 395.
[356] Journal of Anatomy and Physiology, Vol. X. [This edition, No. VII.]
[357] Entwicklungsgeschichte des Menschen u. der höheren Thiere.
[358] Loc. cit.
[359] Beiträge zur Entwicklungsg. d. Allantois d. Müller'schen Gänge u. d. Afters.
[360] “Abdominal Pores and Urogenital Sinus of Lamprey,” Journal of Anatomy and Physiology, Vol. X. p. 488.
[361] The reverse of the above rule is the case with Raja, in the male of which a closer approximation to the single-duct type is found than in the female.
XI. On the Phenomena accompanying the Maturation and Impregnation of the Ovum[362].
The brilliant discoveries of Strasburger and Auerbach have caused the attention of a large number of biologists to be turned to the phenomena accompanying the division of nuclei and the maturation and impregnation of the ovum. The results of the recent investigations on the first of these points formed the subject of an article by Mr Priestley in the sixteenth volume of this Journal, and the object of the present article is to give some account of what has so far been made out with reference to the second of them. The matters to be treated of naturally fall under two heads: (1) the changes attending the ripening of the ovum, which are independent of impregnation; (2) the changes which are directly due to impregnation.