38 The Journal 
put it, the ‘classical symptcms”’ prob- 
ably constitute a complex character 
whose elements are separately heritable. 
Much more extended and minute re- 
search will be necessary before the 
problems involved in the inheritance of 
fragility of bone are settled, but one 
fact, at least, seems established: that 
it is heritable, and in the general manner 
of a dominant trait. 
One other fact is worthy of note: 
this bone abnormality seems usually 
if not always to be associated with a 
of Heredity 
blue color in the ‘whites of the eyes.” 
It has been noticed ever since 1840 in 
medical literature that there are families 
in which the blue color characteristic of 
the eyes of infants seems to persist 
through adult life, and in 1900 Eddowes 
pointed out that this condition and 
fragility of bone were correlated. This 
abnormality of the eyes appears to be 
heritable and dominant, but as to why 
it should be associated with brittleness 
of bone we have no information at 
present. 
Studying Fruits in Illinois 
Many seedling apples are being grown at the Illinois Experiment Station. Re- 
ciprocal hybridizations between standard orchard varieties and various species of 
the genus Malus have been made, fifty-seven species and varieties which are not 
of commercial importance having been obtained from the Arnold Arboretum at 
Boston. Direct improvement through these violent crosses is not anticipated, 
but it is hoped to acquire valuable information regarding the affinities of the various 
species used, and also to produce material for use in back crossing. Reciprocal 
crosses between standard orchard varieties are also being made in large numbers, 
while a difficult piece of work has been attempted in the reciprocal crossing of 
different strains of the same variety, and different individuals of the same strain. 
C. S. Crandall writes: ‘‘This project has aimed at the selfing of particular indi- 
viduals, and the use on trees growing here of pollen from trees of the same variety 
in orchards 100 miles away and grown under quite different conditions. Con- 
siderable effort has been expended in the prosecution of this project, but up to the 
present time we have recorded no successful pollinations. We have not as yet a 
very wide range of varieties, but as far as we have gone we have encountered com- 
plete sterility both in the selfing within the individuals and in the attempt to use 
pollen of the same variety brought from a distance. The unfortunate feature about 
all the hybridizing work with apples is the mongrel character of the plants on which 
we work. We know nothing of the parentage of any of our varieties and it seems 
quite useless to speculate on what the segregation of characters may be in crosses 
between different varieties. A further discouraging feature in apple breeding is 
the long period required to get results from any particular cross. Effort is being 
made to shorten this period by grafting scions of hybrid seedlings on dwarf stocks 
and growing the plants in pots. This will help some, but at best the attainment 
of results is some distance in the future. We are endeavoring to maintain a reason- 
ably complete record of every step that is taken so that a complete history may be 
available for those who may later continue the work. 
‘In pursuing the projects as outlined above there are a number of minor problems 
that are receiving some attention: such as the retention of the vitality of pollen, 
the period of receptivity, the seed production in hybrid fruits, and the time for 
and percentage of the germination of seeds. On all of these points we are accumula- 
ing considerable information that it is hoped may be of some practical value.”’ 
ee 
