28 
Latent and Semi-Latent Characters. 
tions of descent and therefore of systematic relationship. 
It fully deserves and repays the attention given to it, as 
CELAKOWSKY'S admirable papers show. It is to be hoped 
that others will, following the lines laid down by HEIN- 
RICHER, undertake the task of rendering these characters 
more amenable to study by cultivation, and so bring an 
increased number of them to light. 
The manifestations of latent characters are so rare 
that they scarcely ever lend 
themselves to statistical study 
(p. 19). When they recur 
from time to time they are 
seen to be extremely vari- 
able, since as a rule even the 
B I rarest anomalies are not 
quite the same each time 
they appear. It is easily seen 
in such cases that the varia- 
bility is a unilateral one; but 
the construction of curves 
usually fails owing to the 
sparsity of the material. 
The half races are much 
more favorable in this re- 
spect. Here the deviations 
are by no means so very rare. 
As a rule the normal character still preponderates, but 
material sufficient for statistical study can often be found 
without difficulty. It shows clearly that the variation 
is a unilateral one. The apex of the curve is the mean 
of the normal character, and the deviations all lie on the 
same side. And in ordinary cases they are less numerous 
1 Ber. d. d. hot. Ges., Vol. XTT, 1894, P- IQ7. Plate X. 
5678345 
Fig. i. Half Curves. A, Caltha 
palustris. Curve of the num- 
ber of petals in 416 flowers. 
B, Weigelia amabilis, Curve 
of the slips of the corolla in 
1145 flowers. 1 
