Some Recent Work on Hybrids in Plants . ioi 
the varying value of the two characters is exhibited not in different 
individuals but in different parts of the same individual. An example 
of the first case is seen in the hybrid endosperm, produced by 
crossing white and blue Maize races, in which the flecks of colour 
show all gradations between blue and white, the mosaic being thus 
made up of poikilodynamic pairs of characters. An example of 
“mosaic” formation where the pairs of characters are dichodynamic 
is well seen in the hybrids between the blue and white flowered 
races of Veronica longifolia or the hybrids between races of 
Mirabilis Jala pa described by Naudin in 1863 , where the flowers of 
the hybrid are striped with red and white, the colours respectively 
of the two parents. In “mosaic” formation, instead of the relative 
value of the two characters (or the supremacy of one) being 
constant throughout the whole individual, there may be a different 
value for a single branch, a single cell or even a single vacuole (as 
would appear from Correns’ observation on the varying colour of the 
aleurone grains in the cells of the aleurone layer of the endosperm 
of Maize races). 
The earlier investigations of Correns ( 1900 ) on the behaviour 
of Matthiola hybrids must be mentioned, for in them apparently 
the separation of the schizogonous characters takes place according 
to a law other than that of Mendel. Eight pairs of differentiating 
characters were investigated in hybrids between M. incana and 
M. glabra : five of them were heterodynamic and the other three 
homodynamic, but with one character always much the stronger. 
The five dominant characters and the three stronger characters 
were all derived from M. incana. If these eight characters were 
schizogonous there should be produced, according to Mendel, 
256 (2 h ) kinds of sexual cells, and in the next generation two plants 
exactly like the parents should occur only once among 65536 
individuals. Such a pair of forms was however met with only 
among 16 plants. From this observation and from the fact that 
was certain of the characters were found to be correlated, Correns 
led to the belief that only two sorts of sexual cells arise, but in equal 
numbers, one with all the characters of one parent, and one with 
all the characters of the other. 
De Vries, the evidence for whose results, however, has in the 
main not yet been published, while confirming ( 1900 , A, b) Mendel as 
to the presence of heterodynamic and schizogonous characters in 
many hybrids, as stated above, has found aberrant cases in 
Oenothera hybrids ( 1900 , d). Various forms were crossed, and the 
