McDonald: The Dog's Merciuy, 



269 



towards the apex of each of the awl-shaped filaments — perhaps 

 the term ' staminodal nectaries ' is permissable — there will 

 be a minute drop of honey which has been excreted through a 

 pore. These drops are excreted almost on a level with the 

 stigmas and on the side facing them. Often a drop falls on the 

 stigmas, but it is shortly replaced bv another. 



The flowers of both kinds begin to open before the leaves 

 liave entirely unrolled, and often before the stem has straight- 

 ened itself. The flower spikes on each plant tend to approach 

 -each other, the staminate ones above the foliage. This feature 

 and the yellowish hue of the stamens make the staminate ones 

 more conspicuous than the pistillate ones, which do not reach 

 above the foliage. The flowers of the Dog's Mercury are often 

 •quoted as being pollinated by the wind. There are several 

 circumstances which seem to point to this, such as the apparent 

 inconspicuousness of the flowers and their manner of clustering. 

 The staminate flowers open with some force, and perhaps 

 scatter some of the pollen in the act. They only remain on the 

 spike the day they open, then they fall off to make room for 

 the succeeding flowers of the clusters to open. The foliage at 

 this period does not offer much obstruction to the dissemination 

 of the pollen. The clustering of the pistillate flowers towards 

 the side from which the pollen may be expected also appears 

 to favour wind pollination. However, it is interesting to know 

 that midges and other, chiefly small, insects frequent both 

 kinds of flowers on warm days, the staminate flowers furnishing 

 them with pollen to eat — though their juicy-looking perianths 

 may assist in attracting them — and the pistillate ones with 

 nectar. It is very difficult to follow the movements of such 

 minute and elusive insects on the flowers, but by using patience 

 and stealth the writer has seen some actually licking the honey 

 and others eating the pollen.* 



If, after foraging amongst staminate flowers they adjourn 

 for liquid refreshment to the nectaries of the pistillate flowers, 

 they can scarcely help but deposit pollen on the stigmas on 

 which they alight in order to reach the honey, thus bringing 

 about insect pollination. Moreover, the flowers have a peculiar 



* Some insects, which were seen by the writer on warm evenings flying 

 from one sex to the other where bothi sexes were growing practically to- 

 gether, appeared to belong to a black species of gnat. Several of these 

 were seen to lick the honey. The midge Physchodo was seen on both 

 kinds of flowers, as was also the comparatively large dung fly Enipis 

 livida, and further, he has caught several small ants licking the honey. 



1908 July I. 



