PEDIGREE BREEDING. 



283 



intermediate stages between these two types of permanent variability, which 

 are, I believe, the extremes of one and the same phenomenon. At least, as 

 far as I have observed in decemlineata, I interpret the conditions as stated 

 rather than that there is the fundamental difference between races and species 

 postulated by De Vries. 



PEDIGREE BREEDING IN L. MULTITAENIATA. 



It has been shown that L. multitceniata is the immediate tropical ancestor 

 of L. decemlineata, and lives only upon the southern end of the Mexican 

 highlands. My experience and cultures with this species, covering part of 

 1903 and the years 1904 and 1905, extend and confirm, as far as is possible 

 in three years, the results obtained from the longer continued studies of L. 

 decemlineata. This species, we have already seen, is variable, wide ranging, 

 and gives rise to extreme variations under the influence of changing sur- 



roundings or fluctuations in its environment. My experiments with this 

 species are still going on in the tropics, and I shall give here only such results 

 as bear directly upon the problem of the origin of species. 



In August, 1903, 1 obtained a large number of L. multitceiiiata from Guada- 

 lupe, near Mexico City, which were taken to Chicago and there reared 

 under conditions as nearly normal as was possible. At Chicago these beetles 

 were bred in September and October, giving a progeny of 80 males and 

 71 females, .with 2 males and i female of the species rubicitnda, which I 

 had found at Toluca, but never at Guadalupe. These all hibernated, and 

 there emerged in February of the typical multitceniata 20 males and 26 

 females and 1 male and 1 female of rubicitnda. These were isolated and 



