OVARTKS IN CERTAIN UTUTISll BIRDS. 



71 



had been derived, and had bccomo nearly exhausted : the left ovavy, 

 on the other hand, .sliovvcd little more activity than the (juiescent 

 gla,nd of the autumn months. 



7^ {Falco tinnunculus). The left ovary contained a cluster of 

 eggs of even size with one slightly larger— the left oviduct well 

 developed. The right ovary contained hut six very small eggs, 

 and the oviduct was represented by only a narrow ligamentous 

 strand. 



14'' {Accijnter nisua). Both ovaries were present, the right half 

 the size of the left, and contained small eggs only. 



Of the oviducts the right was double the width of the left and 

 had tlie appearance of having recently passed eggs. 



12" (Accipiter nisns). Butli ova,ries and their corresi)()nding 

 ducts {)resent, the left oviduct being the wider. 



This female had probably quite recently passed her full clutch 

 of six eggs, which were taken from the nest by the keeper at the 

 same time that he killed the parent })ird. The remaining (>ggs in 

 both ovaries were all small. The left oviduct had quickly become 

 reduced in width after jiassing the last of the six eggs, which event 

 must have takeii place not more than two days before. 



From the greater width of the left oviduct in 7'^of the right in 

 14% of the left in 12", we may reasonably infer tliat tlusy had 

 severally l)een the latest oviducts in active service. 



This indicates that either the right or the left oviduc^t may be 

 the functional one — and that one or other may work as tluj 

 maturity of the ova in each respective ovary requires their 

 service. 



In conclusion I would again draw attention to 'J'ables 1. 

 and II. 



In Table I., to ta,ke two extreme instances, out of six female 

 Hen Harriers [Circus cyaneus) exainiiHul/wY:; had a persistent j-ight 

 ovary: out of Jz/i^// female Woodcock [ScoIoixim rvisitV^/rt) examined 

 only one retained the gland on the right sid((. 



if the figures in the two tables are combined w(! get the following 

 results : — 



Grand total, 72 examples of paired ovaries out of 212 females 

 examined, made up of two sub-divisions A and B. 



A. Falconida^ TiG out of 98. 



B. Species from any family other than the 



Falconida3 14 out of 112. 



This shows in rather a startling marnier the frequency with 

 which paired ovaries are found in the Falconida; (or rather in 

 the genera which have come under examination) as conq)ared 

 with any other family of British birds. 



There is a second point of some interest in regard to the 

 anatomical position of the ovaries. In the Falconiche these are 

 symmetrically piaceil and are arranged, almost without exception, 

 parallel to each other, and on about the .san)e level, lying on 

 the kidney of the same side and separated from each other by the 

 vertebiul colunin. 



