Tricotyls as Half Races and Intermediate Races. 349 



But as a rule we find the general relations to be such as 

 are exhibited in Figure 65. This curve has a form which 

 is also commonly seen in other anomalies.-^ 



Whilst dicotyly is a character without variation tri- 

 cotyly is one which exhibits a very high degree of fluc- 

 tuation. The limit between dicotyls and the extreme 

 minus variants of the tricotyls can always be easily and 

 certainly observed ; because 

 the apex of the cotyledon is 

 the first part of it to assume 

 its definitive form, and a 

 cleft in this apex, however 

 small, can be clearly seen. 

 There is therefore no fear 

 that the rarity of such ex- 

 tremes might be due to im- 

 perfect observation. The 

 limits between the remaining 

 smaller groups are blurred 

 and arbitrary. But this dif- 

 ficulty disappears in the eval- 

 uation of the degree of in- 

 heritance, because all the 

 seedlings which exhibit cleav- 

 age in one or both cotyledons 

 are united into a single 

 group and treated as tri- 

 cotyls in the larger sense. 



I shall denote the dicotyl- 

 ous seedlings of tliese races as atavists.- In the sowings 



^ See Chapter TV of this part, and Sur Irs courhcs gaJtonicf.ucs 

 dcs fiionsfruositrs, in tlie Bull. Scientif. dc la France et de la Bel- 

 gique, published by A. Giard, Vol. XXVIl, 1896, p. 397. 



" See above, p. 104. 



29. 



Die. 



Hemitricot. 



Trie. Tetraeot. 



Fig. 65. Schematic representa- 

 tion of the fluctuating varia- 

 bility of tricotyly. The tri- 

 cotyls and the dicotyls con- 

 stitute the two apexes, the 

 hemi-tricotyls and tetracotyls 

 (together with the hemi- 

 tetracotyls) constitute the re- 

 maining ordinates. 



