J. J. Slmpson 
251 
TABLE X. 
Correlation Coefficients between the 
Androecium and 
2ud Component 
Table 
r. 
Ca 
XIII 
•5721 
I. W. Ca. ... 
IX 
•4592 
0. W. Ca. ... 
V 
•4371 
Co 
XVI 
•3174 
This table shows that when the androecium is considered as a whole it is most 
highly correlated with the calyx and least correlated with the corolla. 
V. Morphological Significance of the Statistical Results. 
It is quite clear from the tabulated i-esults that there is a definite departure 
from the usually accepted cruciferous structure in a very large number of the 
flowers of Lepidium Draba which have been examined for this study. This does 
not obtain merely in any one organ or constituent but in all the organs and 
constituents, although not to the same degree in each. 
The statistical results will now be examined from the standpoint of the 
botanist in order (a) to note their morphological or genetic significance and 
ib) in order to see whether these figures throw any light on the evolution of this 
cruciferous plant. 
It is almost axiomatic to state that the "purpose" of a tlower is a purely 
reproductive one and that therefore its existence is justified only in so far as it 
serves to reproduce its kind. But not all the parts of a flower are solely repro- 
ductive in function. Each individual consists of two parts, (1) Reproductive, 
XT) Protective. (1) The reproductive organs are the gynsecinm ($) and the 
androecium ((/), while (2) The protective organs (perianth) are the corolla and 
the calyx. 
One of the organs of the perianth, namely the corolla, is still further specialised. 
The calyx consists of four sepals, green in colour, whose sole function is to protect 
the flower when in the bud, and in many cases these are reflexed immediately after 
the flower has opened up, and are of no further importance to it. On the other 
hand the petals though essentially sepal-like in structure, in this as in the great 
majority of flowers, are not green but of some other colour. In the species under 
consideration they are white. Now although the petals are of great importance 
in protecting the reproductive organs while in the bud their utility does not cease 
