156 Atavism. 



i:)ickc(l all the ears of a small group of plants, and ob- 

 tained the following figures: 



Ears without any branching . . . 191 



Ears with one lateral ear 80 



Ears with two lateral ears .... 136 



Ears with three lateral ears .... 93 



Ears with four lateral ears .... 33 

 Ears with five lateral ears .... 12 



Sum of ears 545 

 The degree of branching in this group was fairly 

 low; nevertheless the apex of the curve of the atavistic 

 ears is distinct from that of the branched ones. This 

 l)henomenon could indeed be easily observed, even with- 

 out any counting, on account of the relative scarcity of 

 heads bearing a single lateral ear, a fact which I have 

 also observed repeatedly since. This is a character of 

 the eversporting variety and suggests the possibility that 

 the one-branched ears which are so common in nature 

 (where the ra/7/c.9a-form, as is well knowni, is not at all 

 rare) presumably constitute the half race; but I have 

 not investigated this point. 



The number of compound ears per plant, and the 

 degree of branching in each, are to a great extent de- 

 pendent on the conditions of life. The stronger the 

 growth of the whole plant, and the richer the foliage, 

 the more pronounced will the anomaly be. Therefore, 

 a more profuse branching of the individual ears usually 

 goes hand in hand with a richness of branched inflores- 

 cences. The branching also manifests a certain periodic- 

 ity. The young plants almost always begin with un- 

 branched ears ; it is not until later that the monstrosity 

 appears, gradually increasing in strength. Then towards 

 the end of the summer I often observed a diminution in 

 the amount of branching and often the formation of 



