REPRODUCTION— CONCERNING EGGS 205 



instances of this occur ; thus the eggs of the Common Snipe 

 are usually pyriform, but examples of an oval shape are 

 common ; the eggs of the Himalayan Solitary Snipe (Gallinago 

 solitarid) are extremely pointed in shape, while those of Strick- 

 land's Snipe (G. stricklandi) are remarkably long, narrow and 

 blunt-pointed. As a rule where these markedly pyriform eggs 

 occur they are laid four in a clutch, and with the narrow ends 

 turned inwards, thus economising space, or what is more to the 

 point, are more perfectly covered by the sitting bird. Thus 

 it would be of great interest if observations could be kept on 

 such nests of the Common Snipe as are found containing the 

 less specialised type of eggs with a view to discover whether 

 incubation is in any way affected thereby. 



We may bring this survey to a close with a few comments 

 on the eggs of that great assemblage of forms which has been 

 aptly grouped under the collective term " Pico-passeres ". It 

 is interesting to note here that while among the " Picarian '' 

 or " Coraciiform " types white eggs are the rule, among the 

 Passerines such are very rare, e.g., Dipper, Sand and House 

 Martin. As touching the significance of this lack of colour we 

 shall speak elsewhere (p. 207). 



Although many thousands of species are included in this 

 great brigade — the Passeres which includes more than half of 

 all the known species of the Class Aves — it is a somewhat 

 remarkable fact that in so far as their eggs are concerned, 

 they present a wonderful uniformity. 



True, indeed, they present variety enough in their colora- 

 tion, which is often of great beauty, but eggs precisely alike are 

 laid by species not even remotely related. Where markings 

 are present they take the form for the most part of small spots 

 and freckles, such, for example, as in typical eggs of our 

 Common Thrush or of the Blackbird ; or the pigment may be 

 deposited in the form of a cap or of a band, or yet again in 

 hair-like irregular lines, as in the Buntings. 



As among species outside the assemblage now under dis- 

 cussion, the eggs of some of these " Pico-passeres " are subject 

 to remarkable ranges of variation. In the case of the Common 

 Cuckoo this variation has a definite and peculiar significance, 

 but this is certainly not apparent in such cases as are met 

 with, for example, in our Common Blackbird {Turdus meruld) 



