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. 1 
Whilst clicotyly 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 these races as atavists. 2 In the sowings 
1 See Chapter IV of this part, and Sur les courbes galtoniennes 
dcs monstruositcs, in the Bull. Scientif. de la France et de la Bel- 
gique, published by A. GIARD, Vol. XXVII, 1896, p. 397. 
2 See above, p. 104. 
Die. 
Hemitricot. 
Trie. Tetracot. 
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. 
