614 MESSRS. J. LEWIS BONHOTE AND F. W. SMALLEY ON 



niatings (Exps. 202 &. 205) may be compared with Exps. 203 & 

 204 *, matings of heterozygote Grizzles, where two Chequered birds 

 turned up, although the Avhole number bred (12 birds) was far 

 too small to give any hope of an approximation to the expectation 

 being attained. Many of the Grizzles in these matings are very 

 white, a factor which would tend to conceal the Chequer markings 

 if present. It is more than likely therefore, that owing to this, 

 some of these so-called Grizzles are in reality Grizzle-Chequers. 

 Taking the Grizzles and Grizzle-Chequers (of Exps. 203 & 204) 

 together, the expectation is 12 Grizzles and Grizzle-Chequers, 

 4 Chequers and 2 Self, and our result, 12 Grizzles and Grizzle- 

 Chequers and 2 Chequers, is reasonably near the anticipation. 

 The expectation in Experiments 179, 193, 195, 196 & 197, 

 was an equality of Grizzle-Chequers, Chequei'S, Grizzles and Selfs, 

 and the result 5 Grizzle-Chequers, 12 Chequers, 5 Grizzles, 8 Selfs, 

 the only real discrepancy here being the overpioduction of 

 Chequers. This apparently merely confirms the conclusion come 

 to in an earlier part of this paper, p. 607, which showed that 

 there is apparently some factor which overrides the Mendelian 

 inheritance, and leads to an increase in the number of Chequers 

 produced. 



Mealies. 



A ' Mealy ' may best be described as a Red Grizzled Pigeon 

 showing Blue. The general appearance may be seen by refer-ence 

 to Plate XXY, and it should be noticed that it has the red bars 

 and white flights characteristic of some varieties of red pigeons, 

 When dealing with the Grizzle-character (G) we had to consider 

 its relation to White, and we came to the conclusion that the 

 White w-as not a colour factor complementary to Blue, but a 

 separate allelomorph ; so that the real gametic formula of a 

 grizzled bird was made up of a compound allelomorph containing 

 three characters — blue, white, and grizzling (B, W, G). For 

 practical purposes, however, the W &■ G combine in their inherit- 

 ance, and thus in the cases we have been considering they have, 

 for convenience, been regarded as a single character (G). 



In considering the inheritance of the Mealies, however, we 

 must again pause to consider whether the factor for Red is to be 

 treated as a colour factor, complementary therefore to Blue, or as 

 complementary to the factor for White, or yet again as a separate 

 allelomorph. 



At first sight it would seem natiiral to consider it an alternative 

 colour to Blue, but if this be the case a certain number of Self 

 Reds should have appeared in our matings. None, however, were 

 produced, though a certain number of Blues have been reared. 



The same argument, though in a lesser degree, should hold 

 good if it had an inhei'itance of its own, and we are thus driven 

 to the conclusion that the Red is a complementary factor to the 

 White. We have also had certain aberrant results (not dealt 

 with in this paper) which point to a curious connection between 

 these colours. 



* This pail- has produced both CG and pure Chequers this year (,1911). 



