Effect of bodily injury on egg laying in fowls

In a previous paper (Steggerda, ’28) it was shown that by the injury or partial removal of the ovary of fowls certain birds were stimulated to lay more eggs. This result appears to be related to the work of Zeleny (’03) on regeneration in Brittlestars, from which he concludes, “the greater the number of removed arms, (excepting the case where all are removed) the greater is the rate of regeneration of each arm,” and also to the work of Hartman (’25) on semispaying of the opossum in which he states, “ a compensatory hypertrophy was noted.” The work of Pearl (’21) on the partial removal of the ovary of fowls is also related; he concludes, “The total number of oocytes developing to visible size in the lifetime of a bird is caused to increase from 33 to 68 percent over the number which develope in the normal unoperated bird.