254 ' PRINCIPLES OF BOTANY, ETC. 
many other botanists, denied that of the cotyledons, 
especially in the class Cryptogamia, (§ 139). Jus- 
sieu alone adds to those plants which have no cotyle- 
don, Gaertner’s acotyledones, such as want the 
rostel. Nature provided plants with their cotyle- 
dons, that they might nourish the young plant in 
its tender infancy. Never yet have I noticed.a single’ 
instance where this wise measure of nature was omit- 
ted. | examined purposely all those plants which 
were said to want the cotyledons, and always met 
with them. ‘That in some plants the existence of 
the cotyledons was altogether denied, and others’ 
were said to have one only, others two, and several 
plants more than two, arose partly from inaccurate 
observation, partly from mistaking a part of the 
plumula for a cotyledon. Placenta or cotyledon, 
(§ 114), is the name of the whole entire substance 
of a seed, not including the parts of the corcle. It 
rises in many plants with the plunaule above ground, 
and is converted into leaves, or, it remains in the 
ground, and, as in the gramina, the first leaf of the 
plumule only rises, which is what some thought to. 
be a cotyledon. In the flax and the species of fir, 
both cotyledons are converted into leaves, and the 
leaves of the plumula are evolved immediately after 
them, and of the same magnitude and appearance. 
Hence it was, that botanists supposed there were 
many cotyledons. The division, therefore, of plants 
in acotyledones, monocotyledones, dicotyledones and 
polycotyledones, 1s erroneous, 
