Increased Blood Sugar in Pigeons. 377 



4. These changes may account for some of the phenomena 

 of xerophthalmia, particularly the drying of the cornea in the 

 later stage of the condition. 



184 (1931) 



Increased blood sugar coincident with ovulation in pigeons. 



By HANNAH ELIZABETH HONEYWELL and OSCAR RIDDLE. 



[From the Department of Physiology, Columbia University, New 

 York City, and the Carnegie Station for Experimental 

 Evolution, Cold Spring Harbor, N. Y.] 



The data of an earlier communication by one of us 1 have made 

 it nearly certain that in healthy pigeons the suprarenals usually 

 undergo extensive and regular enlargement at the period of ovu- 

 lation. This result, in view of many facts which indicate an influ- 

 ence of the suprarenals on the mobilization of sugar, naturally 

 leads to an inquiry as to whether the blood sugar also undergoes a 

 similar and simultaneous increase in amount. The data re- 

 ported here indicate that such an increase of blood sugar does 

 also regularly occur. 



Scott and Honeywell 2 concluded that in non-reproducing 

 common pigeons of unknown sex the blood sugar amounts on the 

 average to about 185 mgm. per 100 c.c. of blood as determined by 

 MacLean's method. This same method was used in the present 

 study and a similar amount of sugar was found for birds not ac- 

 tively ovulating. Ring doves in other than ovulation periods 

 have, however, distinctly less blood sugar. Both of these kinds 

 of pigeons, together with a third group — "scraggly" common 

 pigeons — have been used by us. The "scragglies" are a muta- 

 tional or aberrant form having a quite imperfect epidermal system 

 (including the feathers) and bearing suprarenals earlier observed 

 to show wide variation in size. Because of these variations it 

 seemed desirable to include observations on this group. Males 

 and females, both adult and young, of all the three groups have 



1 Riddle, Oscar, Proc. Soc. Exper. Biol, and Med., 1922, xix, 122. 

 1 Scott, E. L. and Honeywell, H. E., Amer. Jour. Physiol., 1921, lv, 362. 



