Cross-Breeding of Maize and the 
Mendelian Theory. 
BY G. A. PFISTER. 
(Read nth January, igio.) 
In September last Mr. Andrews told you in his lecture on 
Mendelism what the foundations of this marvellous science are. 
He told you who Gregor Mendel was, how he discovered the 
principles of segregation, and how his discovery now enables 
experimenters to work systematically and with a practical 
certainty of the results. 
Permit me, however, to shortly revise the most important 
fact of Mendel’s Principle of Heredity. In the production of a 
new individual the essential feature is the union of two germ cells 
—in plants the ovule cell and the pollen cell. In the first genera- 
tion we will have individuals, which in the case of cross*-breeding 
will carry the character of both parents, although they may not 
be evident ; furthermore, these characters will not be represented 
in equal proportions, but one will be dominant, the other recessive. 
The F (filial) generation shows plants of great variety, some 
bearing the characters of one parent, some of the other, some a 
new appearance. Upon examining and classifying these plants, I 
in three-quarters of them we find the character of one parent 
prevalent — the dominant- -while the other quarter consists of 
plants showing the characters of the other pai'ent — the recessive. 
In the F 3 (3rd filial) generation the Recessive F 2 (2nd filial) 
form only Recessives and can be called pure recessives. The F 2 
Dominant, however, produce Dominant pure, and two-thirds 
impure dominants. 
Mendel, and those who re-discovered his theory and com- 
pleted it, have established a number of laws, which govern the 
production of new individuals. The case which I intend to put 
before you to-night is one of cross-breeding maize, with the 
intention of securing a plant which was suited for ensilage pur- 
poses, the chief requisites being abundance of foliage, a great 
number of corn cobs to each plant, and early development of the 
plant. 1 lie objection will be made that maize is not a suitable 
plant for experiments on Mendelism, on account of its not having 
self-fertilizing flowers, but distinct male and female flowers. 
This makes it also comparatively difficult to secure perfectly 
pure parents. The parent plants, however, were bred from seed 
which had proved constant through many a generation, and 
fertilization took place in separate rooms, where there was no possi- 
bility of carnal pollination thiough wind, by other maize plants. 
