156 ALTERATION OF POSITION. 
position. In the latter case, as often happens im the 
seeds of the orange, the new products are placed by 
the side one of another." 
For other cases of prolification or the adventitious 
formation of buds” on leaves, roots, &c., see under 
Heterotaxy. 
CHAPTER, IIT. 
HETEROTAXY. 
Unpir this category are here included a variety of 
deviations from the ordinary arrangement and position 
of parts which cannot conveniently be classed under 
the preceding or under other headings. The term 
heterotaxy is imtended to apply to the production 
of organs in situations where, under usual circum- 
stances, they would not be formed. It thus does not 
include cases of substitution, where one part is re- 
placed by another, or more or less metamorphosed, 
nor cases of multiplication, nor of prolification which are 
characterised not only by the production of members im 
unwonted situations, but also in unwonted numbers. 
From the very nature of the anomalies, and specially 
from the scanty knowledge we possess concerning their 
mode of development, it is not possible to allocate them 
in all cases correctly, and moreoyer many of them 
might as well be placed in one group as in another. 
Formation of adventitious roots—'This is of exceedingly 
common occurrence in a vast number of plants, so 
much so that im most cases it cannot be considered 
as in any way abnormal; there are, however, a few 
instances where the formation of these organs may be 
1 * Hl. Ter. Veg.,’ p. 364, Adnot. 
