OVARIES IN CERTAIN BRITISU BIRDS. 75 



13a. t May 27th, 1911. Norfolk. Age two years. Two 

 ovai-ies present and equally developed. I examined this bird the 

 day after death ; it had been exposed to the sun, so was somewhat 

 decomposed, but I was able to preserve the ovaries. Its six fresh 

 eggs were also taken by the keeper. 



14^t June 8th, 1911. Suffolk. Second year. Both ovaries 

 present. The left containing small and larger eggs. The I'ight 

 with small eggs only. The two oviducts well developed, that 

 of the right being twice the width of the left. The ostium 

 abdominale of the left duct is well shown in this specimen. 



Kestrel {Falco tinnuncidus). j^. 

 (PI. II. figs. 11^-8^) 



lb. January 15th, 1901. Norfolk. Adult. Two ovaries 

 present, but not equal in size, the right ovary being about half 

 as large as the left, but the oviduct was more prominent in the 

 right. 



2b, * June 7th, 1909. Suffolk, Adult plumage. Two ovaries 

 present, the right small, the left quite four times as large as the 

 right. Eggs of two sizes, the larger of a pale cream, a few of the 

 smallei- that were scattei-ed were of a rich yellow colour, 



3b,* June 7th, 1909. Suffolk. Adult. Two ovaries, the 

 right a small dark gelatinous mass with small eggs ; the left about 

 six times as large and contained eggs of various sizes of a yellow 

 colour, a dark gelatinous mass being in the centre. 



4b. May 24th, 1910. Norfolk. Adult plumage. Two ovaries 

 about equal in size, the eggs in the right ovary somewhat the 

 larger. 



5b. May 25th, 1910. Suffolk. Second year's plumage. Two 

 ovai'ies present. The right in a fragmentary state but containing 

 a few eggs of two sizes. The left ovary was about six times larger, 

 with eggs of various sizes, none large. 



Gb.§ January 6th, 1911. Norfolk. Second year. Both ovaries 

 present. The left as large again as the right. Eggs small and of 

 uniform size. Both oviducts thin ; the left very attenuated. 



7b.* May 10th, 1911. Suffolk. Two years old. Left ovary 

 full of eggs of uniform size, with the exception of a single larger 

 one. Left oviduct exceedingly well developed, right ovary small 

 and fragmentary ; six small eggs only ; right oviduct a fine 

 ligamentous sti'and. 



8b.* May 26th, 1911. Suffolk. Age two years. Both ovaries 

 present. The left larger and full of eggs, the right ovary smaller 

 with fewer eggs, two of which were, however, larger than those in 



* Preserved as a museum specimen. 



f Stereoscopic photograph of the ovaries in situ. 



X Sections of the right and left ovaries ; photographs of the same. 



§ Stereoscopic pliotograi)h of the ovaries in situ. 



