OUTLINE OF STRUCTURAL BOTANY 35 
the level of the origin of these members and, as will be seen, in each 
case the members are not only regularly but typically disposed since 
we have, in the case of the Iris, three members of each of the four 
whorls, while at the inner whorl, the fifth, the ovules are shown as 
two for each cell of the ovary or, for each border of the folded leaf 
of which the cell is supposed to be formed. In the other case the 
members are five in each of the whorls and, like the first, the members 
of one whorl alternate with those of the adjoining one and are sym- 
metrically placed, 
But while the general plan may remain, many modifications of it 
may occur, for example: the five members in the whorl of stamens 
may be doubled or multiplied several times. On the other hand, some 
one or more of the members of one or more of these whorls may be 
suppressed or, as frequently, it is merged with a neighboring member. 
Thus, in the case of the lily, there are two rows of stamens of three 
each, while as we see in our diagram of the iris there is but one row 
of developed stamens while another row, indicated by the crosses, re- 
mains undeveloped. Also a single member of one or of several of the 
whorls may be suppressed as it happens in the great mustard family 
where we have four sepals, four petals, four long and two short sta- 
mens and one pistil composed of two united carpels. 
Besides the multiplying of the whorls in some cases and the sup- 
pression of the whole or a part in other cases we find frequent in- 
stances in which the members of some or of several of the whorls have 
been moved toward one side of the peduncle and as a result we have 
a one-sided flower as in case of the pea. 
This, like other parts of the delightful study of botany would Be 
an interesting topic to pursue much more in detail were the space 
available. 
ARRANGEMENT OF FLOWERS. 
The arrangement of flowers on the flower stem constitutes one 
of the means of identifying the different species of the plant. 
When the single flower finds itself the sole occupant of an 
isolated portion of the stem it is said to be solitary as it is in case 
of the violet or the tulip but very frequently the flowers are disposed 
