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the characters under discussion the genes are mutually quite independent 
of one another. It is most noteworthy that there exists between the 
factorgroups for different characters a closer relation than between 
the factors for the same. Further investigations must show to what 
extent this phenomenon occurs in other cases and whether it is 
always coupled with a tendency to preserve the complete image of 
the parent forms. | 
In the case here deseribed the genetic correlation is incomplete. 
As is clear from the tables plants are found, which for some characters 
more nearly approach the one parental form and for others are nearer 
to the second. The number in which the different combinations occur, 
cannot be determined as is done bv other investigators for their 
crossings, also because ordinary correlation plays through it and still 
further obliterates the separation between the groups. If at all, the 
ratios could only be found by much more detailed investigation ; 
but it is clear from the foregoing that by this means some insight 
into the phenomena may be obtained. 
The characters mentioned all belong to flower or seed, the fruit 
might be added since a very close relation exists between the size 
of the fruit and that of the seed. I am also engaged in tracing the 
relation of the characters mentioned to those of the vegetative organs. 
I am, however, prevented by circumstances from completing this 
investigation in the near future. 
The results of the investigation may be summarised as follows: 
In hybrids of Linum usitatissimum and L. angustifolium an in- 
complete genetic correlation exists between the groups of factors or 
genes for length, breadth. and colour of the petal and length and 
breadth of the seed; whereas on the other hand the factors for the 
same character are completely independent of one another. 
The inter-relation is snch that there exists a tendency to approxi- 
mate to the combination of characters as it occurs in the parent forms. 
The genetic correlation expresses itself apparently as a phenomenon 
of the ordinary correlation of fluctuatingly varying characters; 
the latter correlation which also occurs, plays only through the 
former. 
Botanical Laboraiory. 
Grroningen, 3 Oct. 1912. 
