1912] HASSELBRING—CUBAN TOBACCO II9 
each of these types were collected and brought to the United 
States. These seeds were grown at Flint, Mich., during the 
summer of 1g10. 
It is in the first crop from seed imported from Cuba that the 
splitting of the type into numerous varieties has often been reported. 
The plants in the pure line cultures in Michigan, however, showed 
no signs of such splitting. The plants resulting from the mixed 
seed of 10-15 plants of each type were entirely uniform and similar 
to each other. In all their important morphological character- 
istics they were identical with their parent plants grown in Cuba 
the year before. In some minor characteristics some types differed 
from the plants grown in Cuba. The leaves were of a darker 
green and the plants generally were taller and more vigorous in the 
more fertile soil of Michigan. In so far as there was any detectable 
influence due to the new environment, all the plants of a particular 
type reacted alike. 
Discussion 
It appears from the foregoing experiments that when pure strains 
of tobacco are selected from the mixture grown in Cuba and 
brought into a new environment in the United States, these pure 
strains show no breaking up of the type due to the new environ- 
ment. The slight changes which are observed in the plants 
affect all the plants of one type alike. 
The effects observed by SHAMEL and CoBry and others are 
attributable to the fact that the seed was derived from a mixture 
of types. Since a great number of types occur in the fields of 
Cuba, it is not necessary to invoke the doctrine of “breaking up of 
types” to account for the appearance of numerous varieties when 
Cuban seed is sown in the United States. 
The same principle applies to tobacco and other plants culti- 
vated in countries where agriculture has not reached a high state 
of development, and where the concept of an agricultural or horti- 
cultural variety hardly exists. In Cuba I have cultivated tobaccos 
from a number of districts in Mexico, and find that these are also 
mixtures of types which resemble in their general appearance the 
Cuban types and probably belong to the same group of elementary 
