Kleinere Mitteilungen. 121 



irregularly distributed over the tree. In some distinct parts of a single 

 tree other property-forms prevail, other factors of a distinct quality, or 

 even a group of factors, prevail than are met with in other parts of the 

 very same tree. 



I mean that I have directly proved the case in this paragraph. 



S 2. 



The fact that the various factors dealing with one special definite 

 property can be irregularly spread over the plant may so far have the 

 practical significance that in general one must take good care, in the 

 technique of exact research into heredity, that all seeds from all parts of 

 the plant are included in the investigation. 



Time will show how far these results are of influence on the technique 

 of grafting, slipping etc. where these are veritably only parts of the mother- 

 plant and thereby possibly have disposal of fewer factors. 



Now in my former essay I have introduced the theory that the 

 "modification" of plants which have been subjected to different external 

 conditions might be function of the phenomenon that more factors of one 

 property are present; so that under different circumstances others of these 

 factors would predominate, whereby the habitus of the plant would be 

 liable to alteration. The more there are of these factors the more plastic 

 is the whole plant; on the other hand the less plastic, the worse equipped 

 in the struggle for existence. In practice we have announcements made 

 from time to time with great persistence respecting the degeneration of grafts. 

 Deeper research will have to show how far this degeneration may actually 

 consist with regard to the considerations above mentioned, since such a 

 graft is realy an incomplete mother plant with diminished plastic capacity, 

 and would consequently be individually weaker. 



The phenomenon of the presence of more factors of a definite property 

 is therefore of so great importance in the study of the theory of heredity 

 that in the course of time it may even develop into a "standard". 



Where results, such as those dealt with in both of my treatises, may 

 be less strikingly if one knows with certainty that the plants concerned were 

 very much bastardized, there the difficulty begins to arise in those cases 

 with which literature deals, where further factors for one property appear 

 to be present in pure lines. The question will present itself as to what 

 is realy the criterion of pure line in the sense of a homozygote; what 

 is the boundary between bastard and pure line when we do not know their 

 origin; and, when one is in a position to isolate a single plant which, if 

 need, be remains eternaly constant in its posterity, what standpoint has 

 this "pure line" then to take opposed to the fact that in this same pure 

 Une more factors of one property are present, apart from the very great 



