FURTHER STUDIES ON THE INTERRELATIONSHIP 



OF MORPHOLOGICAL AND PHYSIOLOGICAL 



CHARACTERS IN SEEDLINGS OF 



PHASEOLUS 1 



J. ARTHUR HARRIS 



StaHon for Experimental Evolution, Cold Spring Harbor, N. Y. 



\ 



Introductory Remarks 



In a series of papers published during the past several years I have 

 emphasized the importance of investigations of the relationship be- 

 tween the morphological and the physiological characteristics of the 

 organ and of the organism. 



The structural variations of the organs of which the organism is 

 made up are the resultant of intrinsic and extrinsic factors — of heredity 

 and environment, or of nature and nurture. Morphogenetic processes 

 must, therefore, be investigated by physiological methods, and be 

 interpreted in physiological, and ultimately in physical and chemical, 

 terms. 



The purpose of this paper is to supplement and extend the results 

 of an earlier study^ in which it was shown that in bean seedlings char- 

 acterized by certain morphological variations from type, the develop- 

 ment of primordial leaf tissue is less than in normal controls grown 

 undeii conditions as nearly as possible identical. The data then 

 available indicated that a reduction of the volume of primordial leaf 

 tissue is associated with abnormalities of all the types studied, but 

 that the type of variation influences, in some degree, the amount of 

 reduction. 



In these first experiments the conclusions were based on primordial 

 leaves only. 



The use of such leaves has the obvious disadvantage that they 

 are completely formed in the seed, and undergo merely an enormous 

 expansion (and an undetermined amount of differentiation) in the 



^ Studies on the Correlation between Morphologic^il and Physiological Char- 

 acters, V. Studies I-IV of the series are to be found in * k'nctics i: 185-196. 1916; 

 2: 186-212. 1917; 2: 282-290 1917. 



2 Harris, J. Arthur. Studies on the Correlation of Morphological and Physio- 

 logical Characters: The Development of the Primordial Leaves in Teratological 

 Bean Seedlings. Genetics i. 185-196. 1916. 



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