Half Races ivith Heritable Fasciation. 503 
eties distinguished in the first part of this volume (p. 18). 
In the former case the anomalies are rare and their fre- 
quency can not be increased by selection to any consider- 
able extent. In the second case the f asciations occur even 
in the field in obviously larger numbers ; and it is only 
necessary to isolate the examples in question in order to 
be in immediate possession of a race producing f asciations 
abundantly. These experiments are perfectly analogous 
to those which we have described in the case of other 
anomalies and especially to those relating to tricotylous 
and syncotylous cultures (see page 343). Nevertheless, 
in the case of f asciations, we have by no means so strin- 
gent a character to select by, as is presented by the per- 
centage hereditary values, calculated from the seedlings 
of tricotylous races, and therefore the subsequent devel- 
opment of the race after the initial isolation is a matter 
of much greater difficulty. 
Postponing the consideration of the eversporting vari- 
eties or intermediate races to the next section, let us here 
attempt to obtain some insight into the races in which the 
anomaly occurs more rarely. Unfortunately, in many 
instances the available data are not yet sufficient to enable 
us to decide with perfect certainty to which of the two 
types a given case belongs. 
Fasciations occur in so many commercial varieties that 
they are accessible to everybody; sometimes even the 
variety owes its name to the frequency of this character, 
as, for instance, the Sword-elder (Sambucus nigra fas- 
cia fa} ; or it may be an almost constant attribute of the 
cultivated sorts, as in the Japanese spindle-tree (E-ron\- 
iiuis japonica. Fig. 112). When the varieties are either 
largely or exclusively multiplied in the vegetative way, 
it is possible that the anomaly, although only heritable 
