NOTES AND LITERATURE 



HEREDITY 



The Fifth Report of the Evolution Committee of the Royal 

 Society (London), like the preceding reports of this committee, 

 is full of exceedingly interesting results of experimental work. 

 Professor Bateson's committee is doing much to unravel the 

 tangled thread of Mendelian inheritance. In the report in ques- 

 tion I. B. J. Sollas gives the results of studies of color inheritance 

 and of the inheritance of supernumerary mamma' in guinea pigs. 

 The color factors recognized are : 

 G = factor for agouti ticking of the hairs. 



Albinos with which he worked had colored points, hence in 

 them the factor C was not absent, but either merely deficient or 

 controlled in such a M ay as to confine color to the extremities. 



The colored forms fall into two series— one black-eyed, the 

 other ruby-eyed. In the series of black eyes we have the three 

 color types agouti (GBRChC), black (BRChC) and red (BRC). 

 In the ruby-eyed series we have cinnamon (GRChC), chocolate 

 (RChC) and red (RC). The author is not entirely clear in 

 the explanation of some of his formula?. For instance, he offers 

 no explanation why B does not occur in the hair of the red type 

 in the black-eyed series. He does state, however, that in agoutis 

 red spots occur because B fails to develop. Red spots occur also 

 on black individuals for the same reason and on cinnamon indi- 

 viduals because of the failure of the chocolate pigment to de- 

 velop. Each of the colors has one or more dilute forms. 



The method of inheritance of supernumerary mammae was not 

 clearly made out. Several dwarf individuals occurred. Only 

 one of these lived to maturity. 



Miss AVheldale, in the same volume, gives further observations 

 upon the inheritance of (lower color in Antirrhinum majus. A 

 chromogen (Y) allied to the flavone series of coloring matters 

 appears to be the basis of color in these flowers. From this a 

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