228 



THE AMERICAN NATURALIST 



[Vol. LIII 



In addition to these individual progenies of the sister 

 plants, nos. 12 (a), (b), (c) and (d), selected from the 

 progeny of the mother plant, no. 12, in 1916, a mixed lot 

 of seed was harvested from several other sister plants 

 which had blossomed. Fifty-six plants were grown from 

 this mixed lot of seed, all averaging six to six and a half 

 feet in height, and all blossoming. In this lot of plants 

 there were no indications of Mammoth types and so far 

 as could be determined with the eye, no intermediate 

 forms were present. 



From the inheritance behavior of the sister plants, nos. 

 12 (a), (b), (c) and (d), it is evident that pure Mammoth 

 types, breeding true, and intermediate inconstant types 

 appeared simultaneously in the progeny of the original 

 mother plant, no. 12. These intermediate plants behaved 

 as hybrid forms,' in that they gave rise in their progeny 

 to a certain percentage of typical Mammoth, non-blossom- 

 ing types. Since the progenies of the two sister plants, 

 nos. 12 (e) and (d), were handled under similar condi- 

 tions from the time the seed were sown, it is e\ddent that 

 the mother plant, no. 12 (c), yielding 14 Mammoth plants 

 in n total of 4!> jtlaiits. was ooiis^idorably more prolific in 

 MniiiUM.th iihlividuals than the sister ].lant, no. 12 (d), 

 whicli yicld.-.l (uily tw.. Mannnoth individuals in a total of 

 48 plants. 



It is of interest to note that Lodewijks (1911) in work- 

 ing with to])aceo in Java, has observed the occurrence of 

 Mammoth types which breed true and also intermediate 

 or inconstant races which break up into Mammoth or 

 Giant forms a])proximating the theoretical Mendelian 

 ratio of 25 per cent. 



Lodewijks regards these inconstant races as hybrid 

 mutations and -tatc- the rt^snlt- of hi- invcstiu-ations as 



