266 BEAN. 



All types in HI aie derived from two types or elementary species, A' 

 B-' C^ and A'^ B* C", A, B, and C being separaljle unit characters that 

 obey Mendel's laws in cross mating. 



Let A represent a Mendelian character that is variable and the differ- 

 ences of which are hereditary. Let B and C represent similar characters. 

 The exponents represent the degree of difference between the characters, 

 any two adjacent ones being so slightly different from each other as to 

 appear to be exactly alike, but the difference between alternates is sufficient 

 to be recognized and those that are far apart, as A^ and A^", are extremely 

 different. Some of the intermediates may have disappeared leaving gaps 

 not bridged over by living forms. The differences may have accumulated 

 gradually throughout the time of the evolution of the structure and each 

 one of the series now existing is fixed within the limits of environmental 

 variation. 



In order to illustrate the application of this scheme to the Filipinos 

 under consideration, suppose that the three characters, stature, cephalic 

 index, and nasal index are represented by A, B, and C, respectively. Let 

 A^ be a stature of 145 centimeters, and A" a stature of 190 centimeters, 

 with the other powers of A equivalent to the intervening statures at 

 intervals of 5 centimeters for each power. Let B' represent a cephalic 

 index of 73.5 and B'" one of 95.0, and C^ represent a nasal index of 

 55 and C" one of 100 with intervening indices accordingly, represented 

 by the intervening powers of B and C. It will be seen that the exponents 

 represent fairly well the summits of the curves of stature, cephalic index, 

 and nasal index, therefore it may be inferred that the choice of values 

 represented Ijy the exponents is good, because they are actual points 

 about which the characters fluctuate presumably by reason of enviroment. 

 A hypothetical individual in which the gametic constitution is A' A'' 

 g3 gs Q2 Qc^ ^y^g i-ggyit of the marriage of two individuals with a 

 gametic constitution of 2A^ B'' C^ and SA'^ B^ C, respectively) wlien 

 married to an individual of like gametic constitution, has the possibility 

 of producing eight types that breed true and may be called elementary 

 species (II and III). What really takes place among men remains to 

 be determined, but if Mendelian characters in man follow the same course 

 that they do among animals and plants in cross breeding, the above 

 possibility becomes a strong probability. 



We may now proceed to find what combinations of stature, cephalic 

 index, and nasal index are found among the 377 Filipinos under con- 

 sideration, and in this way select types that represent more or less homoge- 

 neoiis entities from which inferences may be drawn in confirmation of, 

 or opposition to, Spillman's ideas regarding elementary species, especially 

 in reference to man. These inferences can be firmly established only by 

 measuring three or more generations in many families. 



