^77 



It is, however, not only the momentary displacement of the enzymatic 

 functions which can act disadvantageously on the organism, but the number 

 of subsequent phenomena must necessarily be connected with it, which will 

 manifest themselves onh^ in the next generation. If, for example, we keep 

 in view the lengthening of the period of growth, induced, as experience 

 shows, by an excess of nitrogen, the immediate result is that the production 

 of seed, which normally occurs at the period of the greatest amount of heat 

 and light, is carried over into a cooler time when the light is poor. The 

 seed thus produced, therefore, does not have sufficient time and proper 

 climatic conditions to carry on all the processes necessary for the formation 

 of reserve materials. The seed is harvested in a condition in which the 

 mobilizing enzymes are still considerably active and it, therefore, is suscep- 

 tible to attacks by parasites affecting the fully matured seed. It has been 

 proved experimentally that immature seed is destroyed more quickly by 

 moulds. Even if the immature seed is not destroyed, and develops the 

 following season, the plant thus produced will necessarily be influenced in 

 its first growth by the greater amount of water content in the seed and the 

 lesser amount of reserve materials. In this connection the following gen- 

 eration is the product of the preceding one, and, therefore, will reproduce 

 by inheritance conditions of weakness. 



Everything that is true of the seed, must also hold good for all other 

 permanent organs. Ihe bud and the maturation of the branch are, in the 

 same way, the product of the preceding period of growth and the manner 

 of their further development depends primarily on the degree of maturity 

 to which they attained in the previous year. 



Displacements of the enzymatic functions, therefore, are continued 

 from one period of growth to another and the diseases, subsequently 

 described, are examples of the inheritance of physiological disturbances. 



Albinism (Variegation). 



The phenomenon, sought by gardeners and propagated by grafting 

 (which may, in fact, be carried over to the stock), manifests itself in the 

 whitish appearance of places which sometimes have a circular form in the 

 diachyma (mesophyll), sometimes appear as wedge-shaped stripes between 

 the ribs, and sometimes as connected zones along the edge of the leaf. The 

 intensity of the white coloration varies. The most diverse transitions from 

 the purest white to quince yellow are found, which in many plants give still 

 further color shades because of the occurrence of reddish tones. In this 

 way is produced the phenomenon called variegation. 



A very well-known example of this white spotted condition is found 

 in the ribbon grass of our gardens (Phalaris arundinacea L., Phalaris picta 

 L.), in which the white parts occur alternately as stripes between the veins. 

 A toy species of the ash leafed maple (Acer Negundo L.) is still more 

 striking. At times this shows perfectly white foliage. The family of the 

 Aroideae might be named as examples of the occurrence of variegation as 



