Varietäten etc. — Physiologie. 37 



There is a strong tendency for the dwarf form to breed true. 

 In a total of eighty-one plants grown from seed of a dwarf there 

 were seventy two dwarf plants, eight classed as intermediates, and 

 one that was robust, 



It is difficult to describe the dwarf type in terms of characters 

 that have been lost or gained. The smaller and crinkled leaves and 

 the shortened internodes are evidences of reduced or arrested 

 growth. In the marked development of branches from the base 

 there is increased growth or at least development of buds that 

 usually remain dormant. 



There is no series of characters of either H. oculiroseus or 

 H. Moscheutos that can be considered as combining in hybridization 

 to give the dwarf. 



The simultaneous appearance of variations involving modi- 

 fications of groups of characters and of intermediates of various 

 kinds exhibit sporadic variations of various degrees of intensity 

 quite in line with the general evidence of the sporadic nature and 

 Wide ränge of such variations. Jongmans. 



Shedd, O. M., Variations in mineral composition of sap, 

 leaves, and stems of the wild grape vine and sugar- 

 maple trec. (Journ. Agric. Research. V. p. 529—542. 1915.) 



There is considerable Variation in the composition of the sap 

 of the wild-grape vine when collected at the same time from two 

 different points. This has been the case for two seasons. 



Large differences in the composition of this sap were found 

 when it was collected at the same point on the vine at different 

 times during the same season. The minerals in the sap are higher 

 at the end of the sap flow than at the beginning. This has also 

 been proved for two seasons. 



The widest variations in the composition of this sap were found 

 when it was collected at the same point on a main branch of the 

 vine at the beginning of the sap flow during four successive years. 

 The periodic loss of sap greatly weakened this branch, and there 

 was also a steady decline in the mineral components of the sap 

 taken from it, particularly potassium and phosphorus, 



There was found a considerable Variation occurring daily in 

 the composition of this sap. The mineral constituents were generally 

 higher during the day and the sap had a more uniform composition 

 during the night. 



The young leaves and stems of this vine at the same stage of 

 growth were also found to vary considerably in composition during 

 different years and also in the same season. 



The sap of the same sugar-maple tree was found to vary 

 widely in composition when collected at the same point on the 

 tree during two successive years just after the sap flow had 

 commenced. 



The mineral composition of the sap of the water-maple tree 

 was found to be different from that of the sugar-maple. 



The ratios of calcium oxid to magnesium oxid and potassium 

 oxid to sodium oxid, together with other factors, demonstrate that 

 the differences in composition cannot be altogether explained as 

 being due to a dilution of the sap from the water in the soil. 



It has been shown that the sap has a variable mineral com- 

 position which influences the structure of the growing parts and 



