DR0SERA MACRANTHA AND D. STRICTICAULIS 39 



other factors being unknown to me, I refrain from pressing the 

 point. The feathery styles suggest wind-pollination ; but the 

 pollen is rather scanty and moist, and is not blown from the 

 anthers even by a strong wind. 



I have frequently wondered why the flower of D. macrantha 

 is white. A possible reason has occurred to me. I judge that 

 of all colours (not even excepting green — though considering its 

 immense importance to plants it is scarcely pertinent to include it 

 in this connection) white may be produced by plants with the 

 minimum of expenditure ; a flimsy aqueous tissue, well aerated, 

 is all that is required, and the petals of our Drosera are of such 

 tissue. A coloured petal must contain, in addition, some colour 

 substance. Now D. macrantha has survived by reason of the 

 strict economy it practises ; its stem is as slender as possible, and 

 its leaves, in addition to their normal function of assimilation, 

 serve as climbing organs. What wonder, then, if equally rigid 

 economy obtains in the flower, the most expensive portion of the 

 plant ? The flowers vary in size and number in accordance with 

 the plant's state of nutrition or vigour. The plan seems to be to 

 produce as large a number of flowers as possible, even at the cost 

 of some loss of attractiveness ; and if the blossom must be ephe- 

 meral, this is, I suppose, the best plan. 



My census figures show that D. stricticaulis is far more 

 successful than D. macrantha in securing pollination. I have not 

 previously taken a census, but I have yearly noticed that the 

 latter is a " shy seeder," while the former fruits freely. So far as 

 I can judge, 1910 (when my census was taken) was quite an 

 average year with both species. Of the thirty-three D. macrantha 

 plants fourteen (two hundred and ninety-five flowers) produced no 

 fruit whatever, while of thirty-seven D. stricticaulis only five 

 (twenty-four flowers) met with a similar lack of success. In both 

 species the fruits split septicidally into three elliptical flimsy 

 chartaceous black valves, each a boat-shaped dish full of seeds. 

 These valves diverge as far as the persistent shrivelled corolla will 

 allow. In the course of its growth the fruit splits the base of the 

 corolla, so that ample openings are provided for the egress of the 

 tiny seeds. These look like worthless chaffy scales, rather than 

 specks of latent life. They are scattered by the wind. They 

 germinate in about six weeks at the ordinary winter temperature 

 (about 60° R). There is no perceptible swelling. A tiny caulicle 

 emerges and a short root is developed ; then a slender flat arm 

 terminated by a tiny tightly-clenched hand appears ; soon the 

 finger-like tentacles expand, and the baby leaf is ready for work. 

 The cotyledons remain within the seed-case. The young leaves 

 of both species are spathulate, the flat almost linear petiole 

 expanding at its apex into a nearly orbicular lamina. The latter 

 is not peltate with centrally attached petiole as in the adult form. 

 Even in the early stages the seedlings of D. stricticaulis look more 

 green and vigorous than those of I), macrantha. I raised a few 

 seedlings of both in 1907 ; these went to rest at the end of spring, 

 and their pots were left dry till the advent of the 1908 wet season ; 



