Vol. xxxiii.] 48 



times, my attention was drawn by Mr. Hellmayr to a short 

 notice by Townsend & Hardy in the f Auk/ 1909, pp. 78-79, 

 in which the authors attempted to prove, from the measure- 

 ments of a small series of House-Sparrows from New 

 England and Liverpool, that the House-Sparrow, since its 

 introduction into North America had increased in size. 

 The average wing-measurement of 8 males from Liverpool 

 is given as 75*5 mm., while 18 males from New England, 

 shot in the same year (1907), average 77*3 mm. The 

 authors believe that the explanation of this strange pheno- 

 menon lies in the struggle for existence and in the survival 

 of the strongest and largest specimens in North America. 



" As, however, Townsend and Hardy, in their article, call 

 attention to the fact that it is not certain whether these 

 Sparrows were introduced from England or Germany, or 

 whether the present stock consists of a mixture of Sparrows 

 from both countries, I tried to find a more probable ex- 

 planation in the theory that the English House-Sparrows — 

 like so many other English birds when compared with their 

 Continental representatives — are smaller, as already suggested 

 by Dr. Hartert (Vogel pal. Faun. p. 148), and that the 

 American Sparrows had not been compared with their 

 actual ancestral form. Mr. G. S. Miller has recently shown 

 (Cat. Mamm. Western Europe, p. 494, 1912) that analogous 

 circumstances were the cause of many unfounded theories 

 about the well-known Porto Santo Rabbit (Lepus huxleyi 

 Haeckel). 



" Since then I have endeavoured to collect material to 

 settle this question, and I have come to the conclusion that 

 my supposition is correct. 



"The wing-measurements which I have taken are as 

 follows : — 



" Bavaria (Mus. Munich) :17 c?: average 78'8, variation 

 75-84 mm. 



" Switzerland (Mus. Tring) :5c?: average 79*8, variation 

 77-83 mm. 



"Tyrol and Kraina (Mus. Tring) :6c?: average 81*0, 

 variation 80-83 mm. 



