124 THE GROWTH OF GROUPS 



(lot A). But during the formation of the fourth and 

 fifth batches of eggs, the beetles were kept under normal 

 conditions, and the eggs were also set aside (lot B). 

 Out of lot B, sixty-one beetles were raised, all being normal. 

 From lot A, ninety-six beetles were raised, but only fourteen 

 of them were like their parents, i.e. normal decemlineata. 

 Of the others no less than eighty- two were pallida, and two 

 were of another form called immaculothorax. Both the 

 pallida and the immaculothorax were exactly the same 

 as sports found in nature. We have seen that in 

 nature pallida was much more likely to appear than 

 any of the other kinds of sports, so also in experiment. 

 This is not merely coincidence, it seems significant, but 

 we know not of what. The artificial sports were in every 

 way the same as those found in nature. Among them- 

 selves they bred perfectly true. When crossed with 

 decemlineata they gave a simple Mendelian result, that is 

 to say, in the second generation a quarter of the offspring 

 were of the kind pallida, in body and germ. 



The species decemlineata has a wide distribution over 

 more than the eastern half of the United States. Another 

 species named multitceniata has a smaller area of distri- 

 bution which is quite apart from that occupied by decem- 

 lineata. The area occupied by decemlineata at present 

 is north of the parallel of latitude 29 N. lying roughly 

 speaking between that line and the great lakes. The 

 species multitaniata lives in Southern Mexico, its area 

 of distribution not being continuous with that of decem- 

 lineata. 



Multitaniata gives rise to two other kinds, rubicunda 

 and mclanothorax. It is difficult to decide whether these 

 forms should be called sports or species, since both have 



