MICHIGAN DEPARTMENT OF CONSERVATION

INTEROFFICE COMMUNICATION
April 16, 1934
Memorandum to Lovejoy:
Reference Articles on Photoperiodism and the Sexual Cycle in Birds.
Rowan, The Riddle of Migration,
n , Proc. Boston Soc. Nat. Hist., XXXIX, 151-20s.
Bissonette, T.H., Studies on the Sexual Cycle in Birds,
Journ. Exp. Zool., Vol. 58, p. 281-319
Bissonette, Effect of Light of Different Intensities Upon the
Testicular Activity of the European Starling,
Physiol, Zool. October, 1931, p. 542 -
Bissonette, Light and the Sexual Cycle in Birds,
Physiol. Zool., January, 1932 92-123.
Maxaimov, N. A.; Rozumov, V. I., Borodina, I. N.,
Physiology of Photoperiodism. Proc. All Russian
Cong. Botanists, Leningrad, 1928, p. 42 - .
These papers contain some fundamental facts regarding photoperiodism
and reproductive cycles. While none of them give data on nest studies or
variations in egg clutches, they do give information on changes in sexual
activity as shown by cytological analysis.
Dr. A. 0. Gross, in the Transactions of the Eighteenth American Game
Conference, p. 193, refers to sun spots and their possible effect on reproduc-
tion,
orge . Saunders
n ait logist
BT                                              Game Division