Vol. xxxvii,] 28 



of the breeding-season in high latitudes and tlie length of 

 the Arctic days, also entered into the question. As an 

 example of the former he quoted the case of the Short- 

 eared Owl, Asio flammeus, which normally lays five to seven, 

 and exceptionally eight eggs, but, during vole ])lagues, has 

 been known to lay from ten to thirteen eggs. The consensus 

 of opinion among Scandinavian ornithologists is that the 

 Rough-legged Buzzard, Buteo lagopus, also lays up to six 

 and even seven eggs in Lemming years, and at other times 

 three or four eggs only. On the other hand, such birds as 

 the Wheatear, Meadow-Pipit, and Reed- Bunting lay larger 

 clutches in Iceland and north Norway than in England, and 

 purely northern species, such as the Brambling, Fieldfare, 

 Snow-Bunting, and Lapland Bunting, lay larger clutches 

 than their southern representatives. In these cases climatic 

 and geographical conditions must be the dominant factors. 



Mr. E. C. Stuart Baker also exhibited some interesting 

 series of Cuckoos' eggs to show the evolution which was in 

 course of determining the colour of their eggs. To demon- 

 strate this, eggs of Cuculus micropterus, Cuculus optatus, and 

 Cuculus intermedius were exhibited in boxes so arranged 

 that it was easy to see that each Cuckoo had certain birds 

 which it regularly selected as foster-parents for its eggs and 

 with whose eggs its own agreed more or less perfectly. 

 Other boxes showed eggs placed Avith those of foster-parents 

 with which they were in striking contrast, and which the 

 exhibitor believed were those of birds not selected as foster- 

 parents except under compulsion. 



Mr. Michael J. Nicoll sent for exhibition two new birds 

 from Egypt which had been presented to the National Col- 

 lection by the Egyptian Government, Zoological Service, 

 and which he described as follows (communicated by iMr. W. 

 L. Sclater) : — 



Sylvia norrisae, sp. nov. 



Adult male in breeding-plumage . Crown, ear-coverts, and 

 lores deep glossy black, the rest of the upper parts hair 

 brown ; quills brown, edged on the outer webs with pale 



