Page:A critique of the theory of evolution.djvu/89

Fig. 36. Diagram illustrating a cross between a red eyed male and white eyed female of the fruit fly (reciprocal cross of that shown in Fig. 35).

It has been shown by Sturtevant that in a wild species of Drosophila, viz., D. repleta, two varieties of individuals exist, in one of which the thorax has large splotches and in the