640 Vehicles of the Hereditary CJiaracters. 



groups are regarded as units. Nevertheless, in some 

 places, he has definitely expressed the view that every 

 character which can vary independently of others must 

 be represented by a discrete material vehicle.-^ 



This principle has been largely supported by recent 

 investigations. Morphological elements are coming to 



Fig. 147. Riibus fruticosus laciniafus. The deep dissection 

 of the margin of the leaf, which is the character of this 

 variety, is seen to be expressed both in the foliage leaves 

 and in the petals. Both phenomena are obviously the 

 expressions of the same material vehicle of the internal 

 character. 



be recognized more and more as combinations of units, 

 whilst independence in variation is regarded as the real 

 sign of the existence of separate elementary units. 



^Darwin, Variations, 2d ed., 1875, II, p. 378. Intracellular Pan- 

 genesis (Engl, ed.), p. 19 ff. 



