OVARIES IN CERTAIN BRITISH BIRDS. Of) 



only one (the left) is developed and functional. The 

 right oviduct remains a hydatid ; sometimes is developed 

 anomalously, while the left atrophies ; rarely the two remain, 

 (Pigeons and Parrots)." 



Bovvdler Sharpe * : — " The right ovary of birds is always 

 atrophied, and it is only in rare cases that rudiments of it 

 are found (namely in the diurnal Haptorps). The right 

 oviduct is not so conipletaly atrophied as is the ovary of the 

 same side." 



In the recently published 'Grouse in Jiealth and Disease' 



Dr. E. A. Wilson writes (of that bird)t :—" There is but one 



ovary, and it lies always on the left side of the backbone 



of the bird. This development of the ovary, only on one 



side, is the reason for advising the examination to be made, 



as detailed above, on the left side always." 



This last quotation is interesting in connection with the subject 



of paired ovaries, since over 2000 grouse passed through the haijds 



of the Grouse Disease Committee and were carefully examined ; 



of these nearly a quarter (476) were females, and not a single 



example of a persistent riglit ovary or its remains was found J. 



It is to be noted, however, that if the sexing were carpied out, as 



Dr. Wilson recommended, by examination of the left side, persistent 



right ovaries might have been overlooked. 



Newton § : — '^ In the female a paij.^ of ovaries are developed, but 

 with rare exceptions only that on the left side beconjes 

 functional. In young birds bpth ovidpcts are almost equally 

 developed, but the right one soon becomes reduced to an 

 insigniiicant ligamentous strand alpng the veptral side or 

 part of the kjdney. 



" This one-sided suppression of the organs may possibly be 

 referable to the inconvenience that might be paused were 

 each oviduct to contain an egg rpady to be deposited." 



From the above quotations it will be seen that the majority of 

 the writers do not admit the presence of a right ovary at all \v 

 the adult female. Sharpe speaks of rudiments || of the lighu 

 ovai-y being retained in the diurnal Raptores. Newton very 

 guardedly refers to "rare exceptions" where both qvaries are 

 present, but he does not mention in what species of bii'd these 

 exceptions were found. It is indeed rather doubtful if these 

 instances came under his personal observation ; had they done so 

 he would probably have published the names of the species and 



* Cassell's Natural History, vol. Hi. p. 251. R. Howdler Sliarjjo, 1883. 

 + 'Grouse in Health and Disease,' vol. i. p. 60. 



X (^ut of 17 female grouse that have passed through njy hands in the last fotfp 

 years, three have shown well-marked paired ovaries. — T. E. G. 



ij ' Dictionary of Birds,' ("reproductive organs ") p. 782. Alfred Jfewtqn, 1894. 

 II Italics are mine (T. E. G.). 



Piioc. ZooL. Soc— 1912, Xo. V. D 



