II. FILIPINO TYPES : MALBCON MORGUE. 313 



AMPLIFIED SCHEME FOE HEREDITY. 



In the scheme for heredity D and B represent the honiozygotes of 

 an allelomorphic pair that meet at 1 in sexual union, begin to blend at 

 2, present the picture of a variable blend at 3, and fuse completely into 

 a perfect blend at 4. A horizontal cross section of the diagram at any 

 point represents the relative number of individuals of the different 

 kinds jjresent at that time in the process of amalgamation, provided 

 procreation has been continuous and always with the same relative 

 increase in numbers. The width of the diagram, exclusive of the spaces 

 B", also indicates the amount of variation at any time. D=homozygous 

 dominants; E^homozygous recessives; DE=heterozj'gotes ; B'- (inside- 

 the solid lines) =a variable blend ever increasing in number with each 

 successive generation; while D, E, and DE decrease to disappear entirely 

 at 3. W (inside the solid lines) represents the continuation of the 

 blend without either of the originals of the allelomorphic pair, but with 

 all shades of intervening characters blending in various ways as in- 

 fluenced by ancestry and by environment, until a homozygote is formed 

 at 4. B^ (inside the solid lines) represents the increasing purity of 

 the blend u.ntil at 4 a perfect blend or an elementary species is formed. 



From 1 to 2 True Mendelism exists. Spurious Mendelism is found from 

 2 to 3, and from 3 to 4 No Mendelism is present, but two tendencies 

 prevail: (a) the reversion to type, and (b) the tendency to blend. 



This scheme represents the individual characters but it may also 

 apply to the type composite, although some characters may not follow the 

 scheme but exhibit blending at once when crossed, without intervening 

 Mendelism. Therefore some characters should be represented in one 

 part of the scheme while others are represented in other parts. In 

 t)rpes with extremely divergent characters, such as the black and white 

 coat in guinea pigs, Mendelism may persist as indicated in the scheme; 

 whereas if the types that cross are similar, the result may be a more or 

 less perfect blend immediately. The Mendelism is overleaped and the 

 types pass at once into the conditions represented between 3 and 4, or 

 that of a variable blend with Ko Mendelism. 



The ultimate result of a process where many types are blending will 

 depend upon many factors such as environment, natural and sexual selec- 

 tion, the relative number of each type which enters into the amalgamated 

 product, the dominance of one type over another, the time during which 

 amalgamation has taken place, etc. ; and the elementary species formed 

 may be unlike the original types, yet not a perfect blend. (For example, 

 the Australoid, as a result of crossing the Iberian and the Primitive.) 

 The calculation may now proceed. The relative numl^er of blends in 

 proportion to the number of types is to be considered, also the number 

 of each type present, and finally the condition of the types as to purity. 



