THE EFFECTS OF BILATERAL OVARIOTOMY IN THE BROWN LEGHORN FOWL

¹ Whitman Laboratory of Experimental Zoölogy, The University of Chicago.

1 Complete bilateral ovariotomy in the brown leghorn fowl leads to an asexual or neutral type common to both sexes in many of its characters.

2. The head furnishings which become large and male-like following sinistral ovariotomy remained small and fluctuated little in size following complete bilateral ovariotomy.

3. Following sinistral ovariotomy the plumage becomes male but at a later period, varying greatly in different individuals, it reverts to the female type. In our cases of complete bilateral ovariotomy the plumage became male following the operation and retained this character to the termination of the experiment.

4. Well developed spurs were found in all cases. The amount of spur tissue developed does not seem to be greater in the bilaterally ovariotomized fowl than in those sinistrally ovariotomized.

5. The behavior of these individuals is neither male nor female but neutral. Comparable in this respect to that of the capon.

6. The Wolffian ducts hypertrophy following sinistral ovariotomy. No such hypertrophy is perceptible in the bilaterally ovariotomized fowl, these ducts being small, straight and often very difficult to find.

7. The amount of oviduct tissue varies greatly in the sinistrally ovariotomized fowl. In the cases of complete bilateral ovariotomy here recorded the oviduct is reduced to a very small straight flattened tube, 2-3 mm. in diameter. Very small rudiments of the right oviduct were found in all cases.

8. No changes were observed in size. The birds retained approximately the size of normal hens.