440 NATURAL SCIENCE. Dec, 1893. 



reveals differences between eggs of birds of various species, the egg 

 of a bird paired with an alien male may be distinguished from one 

 laid by the same bird with a mate of her own species. And Mr. 

 A. G. Butler (11) affirms that a canary in his possession laid eggs 

 coloured and marked like those of a chaffinch, when paired with a 

 male of that species. Experiments are much needed on these points; 

 and since we fortunately have in domestication birds nearly allied, 

 yet perfectly distinct in species, such as the Muscovy and common 

 ducks, Chinese and common geese, Guinea fowl and common -fowl, 

 and collared turtle-dove and pigeon, it is to be hoped that someone 

 will be sufficiently energetic to experiment with some or all of these ; 

 hence, he may thus help on the solution of more than one debated 

 question interesting to scientific men in general, for the same series 

 of experiments might be made to throw light on Hybridism as well 

 as on the subject of this paper. 



REFERENCES. 



1 Weismann, A.— "The All-Sufhciency of Natural Selection — II." Contemporary 

 Review, 1S93, and "The Germ-Plasm," 1893, pp. 384, 385. 



2. Darwin, C. — Animals and Plants under Domestication, 2nd ed., vol. i. 



3. Harvey, A. — On a Curious Effect of Cross-Breeding, 1851. 



4. Romanes, G. J.— Nature, September 28, 1893, pp. 515, 516. 



5. "Wallace, R. — " Farm Live Stock of Great Britain," 1893. 



6. Youatt, W. — " The Pig." Sidney's enlarged edition, i860. 



7. McKay, E— " The Book of the Rabbit," 1889. 



8. Godwin, W. — Field, October 14, 1893. 



9. Wright, L.— " The Poultry Book," Popular Revised Edition, 1891. 



10. Newton, A.—" A Dictionary of Birds," Article Egg, 1893. 



11. Butler, A. G. — Zoologist, May, 1893. 



Frank Finn. 



