108 
LOCK: ECOLOGICAL NOTES 
Urban bas made important observations upon the floral 
mechanisms of the Turneraceæ.* I have not had access to 
Urban’s original monograph, and have relied principally 
upon the fairly full abstracts given in Just’s Bot. Jahresb. 
for 1883. But for a complete transcription of the chapter in 
which this observer describes the result of his examination 
of living plants I am indebted to Miss M. A. Graves of 
Cambridge, to whom I desire to express here my very 
hearty thanks for her assistance. 
Gilgt thus summarizes Urban’s observations upon the 
method of pollination in the order The flowers of very 
many Turneraceæ open their petals, which are often brightly 
coloured, in the morning or sometimes not until midday ; 
in the evening they become closed again and withered. 
During the day honey is very abundantly secreted by the 
flowers, and many insects are thus attracted. If, however, 
cross-pollination has not taken place by their aid, self- 
pollination occurs with great regularity, for when the petals 
close they fall together at the apex, and the anthers and 
stigmas are thus brought into close contact, 
UrbanJ described forty-eight species of Turneraceæ as 
being undoubtedly, eight as probably dimorphic, and six 
as incompletely dimorphic. One species§ was in six forms 
homostyled, in six forms heterostyled. The total number 
of species examined was eighty-three. 
The variety of T. ulmifolia known as T. angustifolia is 
stated to be homostyled, and is described at length. This 
description, which was taken from living plants, I shall 
here briefly summarize before passing on to my own 
* Monograph of Turneraceæ, Berl. Bot. Jahrb., vol. II. 
f Engler and Prantl. Nat. Pflanzen!, III., 6 a, p. 64. 
X Loc. Git. 
§ Since these notes were written I learn that this actually applies to the 
species T. ulmifolia. (The reviewer in Bot. Jahresb. gives, as far as I can 
discover, no hint of this being the case.) It appears therefore that the 
heterostylism of certain varieties of T. ulmifolia has already been described, 
but only from herbarium specimens. This being so, it appears unnecessary 
to alter the form of my remarks, whilst noting in this place the earlier 
record of dimorphism. 
