16 



MR. J. LEWIS BOXIIOTE OX THE 



of the birds noted in Table II., one would, in theory, have 

 expected the web to have made its appearance in more than one 

 instance, as the number of DR birds in Mr. Smalley's lofts must 

 be considerable. 



The fact i-emains that a webbed bird has been bred, and if its 

 pedigree were not well-known one would have liad to regard it 

 as a " sport," without being able to accoiuit for its presence in 

 any way. 



So far, therefore, from well-attested evidence of independent 

 breeders, the webbed character seems to be established beyond 

 doubt as a Mendelian recessive. 



In the summer of 1907, however, Mr. Smalley sent me a male 

 web-footed bird (W 69), which I paired at once with one of the 

 progeny (also webbed) of the pair of birds originally given me by 

 Mr. Staples Browne. My object was merely to get a change 

 of blood and to keep up a small stock of webbed birds. 



Both the parents were webbed and, .as we have seen, their 

 ancestry showed that in both families the web had acted as a, 

 Mendelian recessive, so no doubt was felt but that the whole of 

 the progeny would also be webbed. The result of this mating 

 was five birds, of loMchfour tvere normal. 



For the past three years I have carefully mated these five 

 birds and their descendants, with the results as shown in the 

 follovving table : — 



Table III. 



* In both these birds the amount of webbing is just on the line fixed by 

 Mr. Staples Browne. 



If we look closely into the foregoing table, we may note that 

 whenever the apparent Normals are mated together we get some 

 webs. This has been done in experiments 3, 4, and 7, the total 

 result being 12 normals to 6 webs. Were these normals hetero- 

 zygotes Ave should have expected 12 Normals and 4 Webs. 



