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THE POPULAR SCIENCE MONTHLY 



usually these statements are to the effect that the bird's ovary contains 

 "several hundred" ova. 



Table I 

 Showing the Number of Visible Oocytes in the Ovary of Certain Fowls 



Not only is the absolute number of oocytes large, but it is also very 

 much larger than the number of eggs which any hen ever lays. A record 

 of 200 eggs in the year is a high record of fecundity for the domestic 

 fowl, though in exceptional cases it may go even a hundred eggs higher 

 than this. But even a 200-egg record is only a little more than a tenth 

 of the average total number of visible oocytes in a bird's ovary, to say 

 nothing of the probably much larger number of oocytes invisible to the 

 unaided eye, but capable of growth and development. In other words, 

 it is quite evident from these figures that the potential " anatomical " 

 fecundity is very much higher than the actually realized fecundity. 

 This is true even if we suppose the bird to be allowed to live until it dies 

 a natural death. 



An examination of the table in detail indicates that there is no very 

 close or definite relationship between the number of visible oocytes on 

 the ovary and the winter production of a bird. Thus No. 1,367 and 

 No. 3,546 each have about the same number of visible oocytes, yet one 

 has a winter production record 18 times as great as the other. Again 

 No. 71 with the extraordinarily high winter record of 106 eggs has only 

 a little more than one half as many visible oocytes as hen No. 2,067, 

 whose winter production record is only 32 eggs. Again, No. 71 with its 

 106 record has very nearly the same oocyte count as No. 8,010 with a 

 winter record of zero. In general it may be said that the present figures 

 give no indication that there is any correlation between fecundity as 

 measured by winter production, and the number of oocytes in the ovary. 

 Of course, the present statistics are meager. More ample figures are 

 needed (and are being collected) from which to measure the correlation 

 between actual and "anatomical" fecundity. 



