1 8o Hormones and the Behavior o£ Fowl 



Male copulatory behavior was exhibited for approximately one and a half 

 months after which the bird began to lay fertile eggs. 



In order to interpret certain phases of the experiments reported in the pres- 

 ent paper, a new series (Domm, Davis, and Blivaiss^) was undertaken which 

 closely parallels the experiment of Zitrin in certain respects. Nine brown 

 Leghorn pullets, divided into three groups of three pullets each, received daily 

 injections of testosterone propionate. The first group (112 days old) received 

 0.50 mg., the second, which was the same age, received 1.00 mg. and the third 

 (138 days old) received 1.50 mg. daily. All birds were tested and observed 

 daily during the first two months and usually on alternate days thereafter. 



The group receiving 0.50 mg. was injected for one hundred twenty-one days. 

 One of these crowed, circled, and "waltzed"; another crowed biu never showed 

 any particular interest in either sex; while the third was not known to crow but 

 began to chase, circle, and "waltz" shortly before injections were discontinued. 



The other two groups of six pullets are still under observation and have now 

 received daily injections of the amounts indicated for more than one hundred 

 eighty days. All of these are known to crow, chase, circle, and "waltz" and sev- 

 eral have shown weak mounting attempts. Only one of those receiving the 

 highest dosage has actually been observed to mount. This bird grabbed and 

 mounted a squatting female on the one hundred forty-sixth day in the typical 

 male manner. However, copulation did not take place and a repetition has not 

 occurred since, though several weak attempts at mounting have been observed. 

 In all groups, crowing, chasing, circling, and "waltzing" became quite common 

 once these reactions appeared. 



In attempting to evaluate these results one is likely to raise a question con- 

 cerning the relative efficacy of the two procedures employed in administering 

 the hormone, since it is known that a constant source of hormones is necessary 

 for the development and maintenance of many sexual characters. However, 

 until more data are available concerning the development and maintenance 

 of the various sexual-behavior patterns in the fowl the sporadic occurrence 

 of treading females, whether normal or the result of various experimental pro- 

 cedures, must be regarded as exceptional. 



REFERENCES 



1. Domm, L. V., and Davis, D. E.: Proc. Soc. Exper. Biol. & Med. 48:665, 1941; Anat. Recrd. 



8i(supp.):6i, 1941. 



2. Davis, D. E., and Domm, L. V.: Proc. Soc. Exper. Biol. & Med. 48:667, 1941; Anat. Recrd. 



8i(supp.):io4, 1941. 



3. Domm, L. V.: in Sex and Internal Secretions, ed. by E. Allen (2d ed.; Baltimore: 1939), 227. 



4. Davis, D. E., and Domm, L. V.: In press. 



5. Domm, L. V.: Jl. Exper. Z06I. 48:31, 1927. 



6. Domm, L. V.: Biol. Bull. 56:459, 1929. 



7. Lillie, F. R.: Jl. Exper. Z06I. 48:175, 1927. 



8. Benoit, J.: Archs. de zool. exper. et genrl. 69:217, 1929. 



9. Allee, W. C; Collias, N., and Lutherman, C. Z.: Physiol. Zool. 12:412, 1939. 

 10. Hamilton, J. B., and Golden, W. R. C: Endocrinology 25:737, 1939. 



