Analysis of Hetesogeneity in Complex Chakactees 



253 



taken not to allow anything to happen, such as sudden changes of the conditions 

 or violent stimuli which might upset the constitution of some gametes and thus 

 introduce another factor and complicate the results. 



Another example will suffice to show the manner of reaction of these biotypes 

 to these breeding-tests in the testing of biotype 9, as shown in figure 41. Two 

 males and two females, each from classes a and b of this biotype, that had been 

 derived from extracted stocks from the Texcoco colony and had been pedigreed 

 for four generations, were mated and allowed to breed freely and gave in F^ a 

 progeny of 87 males and 101 females, distributed over the four classes common 



Fio. 41. — Breeding record through a series of generations of a race of primary 

 hlotype 9 in h. rnultitwniata, again showing the constancy of the race within this 

 line. 



to thi^ biotype, as shown in figure 41. From these there were taken 2 males 

 and 2 females from each class, except class a, and mated. This group gave a 

 progeny of 136 males and 124 females in Fo. This population showed a group 

 of 7 males and 7 females, which were quite beyond the normal range of this bio- 

 type; they were not removed, but were bred back into the population in the 

 mating for Fg. From this population the usual random matings were made 

 and they gave in Fg 101 males and 102 females. In this population 3 males and 

 4 females stood quite without the range of the normal biotype and were separated 



