XIII.—The Formation, Rupture, and Closure of Ovarian Follicles in Ferrets and Ferret-Polecat Hybrids, and some Associated Phenomena.

Abstract

A few words of explanation are necessary at the outset in connection with the terms used in association with the animals upon which these investigations were made.Dealers in ferrets supply two types of animals—one with yellowish-white fur and pink eyes, which they call “ferrets,” and a second type in which the yellowish fur is intermingled with a varying admixture of brownish or brown-black hairs; the second type they call “polecats.” The polecats of the ferret-dealers are not, however, true polecats, for Miss Frances Pitt, who has bred ferrets and polecats and ferret-polecat hybrids in a scientific manner, and to whom I am indebted for the greater and best part of my information on this subject, points out that the so-called polecat of the dealers is never so dark and handsome in colour as the true polecat. Moreover, as Miss Pitt states, in the true polecat the light marks in front of the ears do not usually join across the forehead, whereas in the polecat of the dealers they form a band across the face; further, when viewed from in front and above, the head of the true polecat has the form of a fairly equilateral triangle, whilst in ferrets and the so-called polecats of the dealers the head, on the whole, has the form of an isosceles triangle.