420 Cutting . — Observations on Variations in the 
inflorescence is passing through a series from the compound spike to the 
simple dichasium, and at the particular point when either a trichasium is 
found or when there is a top flower to a fairly complex inflorescence bearing 
side flowers in a dorsal and ventral position. 
I can offer no opinion as to the external conditions which control the 
formation of these transitional forms of inflorescence. 
In one case an almost symmetrical side flower was found, but even here 
it was a part of a trichasial system. 
It will be remembered that Peyritsch (31), in his various papers on the 
cause of peloria, was of the opinion that in several Labiatae sudden changes 
in illumination induced this condition, and that he brought forward a certain 
amount of experimental evidence pointing in this direction. I have found 
peloric flowers in Galeobdolon luteum , the plant experimented on by Peyritsch, 
in a hedgerow which had been greatly depleted of its shade. 
Last year (1920) plants collected in the neighbourhood of Radlett, 
Herts., were planted in my gardens, some in the shade (under a tree) and 
others in a more open situation. As would have been expected, the shade 
plants flowered (i. e. bore open flowers) later than the sun ones, indeed about 
a week after — those in the sun flowering on May 24, and those in the 
shade on June 1. The general condition of the shade flowers was unsatis- 
factory ; they often withered before they opened ; they were stunted, and, 
so far, one case of fusion has been observed amongst them. On a shoot, on 
which but few flowers were open and those towards the light, a flower was 
found with a bifurcated upper lip. 
The sun plants seemed, on the whole, normal, but one plant bore two 
flowers with lower lips having the middle lobe like the side ones (with two 
lobes instead of three to the lower lip). One of these flowers was a late 
developed one in the lowest verticillaster, and the other was found on the 
third verticillaster in a similar position. 
* Discussion. 
There are a large number of observations showing that external 
conditions (time of year, good or bad nourishment) and the position, advan- 
tageous or otherwise, of the inflorescence on the plant have an effect on the 
number of flowers in a capitulum in the case of the Compositae (35) and on 
the number of members in the whorls of individual flowers in many other 
cases. MacLeod (25) found, for example, that in some plants of Ranunculus 
ficaria the percentage of members in a whorl was smaller under adverse 
circumstances. Correns (8, 9) obtained similar results in Satureia hortensis ; 
Burkill (6) reports that in Bocconia and many other plants examined 
statistically by him the flowers in favoured positions on the inflorescence 
had a larger number of sporophylls, and Salisbury (33) recently notes that 
this is the usual, though not the invariable, state of affairs in the case of the 
