Correlation of morphological variations in the seedling of 
Phaseolus vulgaris 
J. ARTHUR HARRIS AND B. T. AVERY 
INTRODUCTORY REMARKS 
During the past several years one of us has had under way 
extensive experiments on the differential death-rate of bean seed- 
lings. Individuals differing in structure also differ in their capa- 
city for survival under field conditions,* and in such physiological 
characteristics as capacity for the development of the tissues of the 
primordial} and of the subsequent leaves.t{ 
Some tens of thousands of seedlings of known morphologica] 
characteristics have been exposed to risk, as the life insurance 
statisticians express it, in an attempt to determine the selective 
value of the various morphological variations. These seedlings 
were, for technical reasons, necessarily planted in the field at a 
time when the cotyledonary node and the primordial node only 
could be studied. It is evident that the capacity of the plant for 
survival may be in some degree dependent upon characters de- 
veloped later in ontogenesis, but correlated with characters of the 
first or second node of the seedling. 
However this may be, it is certainly true that a full knowledge 
of the morphology and physiology of the variant bean seedling 
demands a thoroughgoing investigation of the correlation between 
the structure of the first two leaf whorls and that of later whorls. 
We have, therefore, been forced to consider the problem of the 
‘morphological character of the leaf whorls produced at the third 
* Harris, J. Arthur. A simple demonstration of the action of natural selection. 
Science II. 36: 713-715. 1912. 
t Harris, J. Arthur. Studies on the correlation of morphological and physiologi- 
cal characters: the development of the primordial leaves in teratological bean seed- 
lings. Genetics 1: 185-196. 1916. 
¢ Harris, J. Arthur. Further studies on the interrelationship of morphological 
and ee characters in seedlings of Phaseolus. Mem. Brooklyn Bot. Gard. 
I, in press 
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