Analysis of Hetbkogeneitt in the Population 



311 



in this year is the early onset of the rainy season, the amovmt and uniform distri- 

 bution of the precipitation, and accompanying this there was an uncommon 

 development in growth and luxuriance of the flora and fauna noted throughout 

 the season. 



In 1907 the season was an average one, and in both determinations the popu- 

 lation showed only restricted ranges in the immediate proximity of biotype 7, 



8— 



25 34 21 



21-eii^ 



Total 1720. 798 Females. 



—145 



Safe^^>-2ii 



45 196 



Fio. 117. — First census at Tierra Blanca In 1906, showing condition in tlie 

 population as a whole and existence of an increased number of isolated groups. 



— «&S 



45 



*H^ 



/ '^ 



I ' i ■* 



-141 

 —283 

 -156 

 S-105 



Total 2475. 



41 42 31 

 1235 Females. 



Pl(3 118. Second census at Tierra Blanca in 1906, showing Increased array- 

 in the' population as a whole and the restriction of isolated groups to a single one 

 present in the males only. 



with no divergent groups. The conditions of the population in the two censuses 

 are shown in figures 119 and 120 ; distribution about like that in 1904 and 1905. 

 In 1908, which was a season in character like that of 1906, the population 

 again showed increased ranges in the array of the central mass of the population 

 and considerable developments of isolated groups. In the first census the two 

 sexes showed essentially identical conditions; the central mass showed a heavy 

 development of biotype 7 and conspicuous showing of 5. Biotype 4 was feebly 



