470 JOURNAL OF SCIENCE. 
therefore usually of inconspicuous colour and of small size, destitute 
of nectar and scent, but the stamens are well-developed, producing an 
immense amount of small and very dry pollen, and the anthers are so 
placed that they are easily shaken by the wind, while the stigmas are 
relatively of very large size. Our tutu plants, Coprosmas and Rib- 
erasses are familiar examples of such anemophilous plants, and that 
they have acquired this character by degradation is very manifest, as 
they belong to groups in which the petals have been well developed, 
and which consequently owed their origin to insect visitors. Even 
among wind-fertilized flowers, some very singular characters prevail. 
Thus Coprosma is always strictly dicecious, while the closcly-allied 
Nertera is as markedly protogynous as is the Rib-grass (Plantago) or 
common Tutu. It is probable that all grasses, sedges, rushes, and 
allied plants which are now wind-fertilized, are like those just men- 
tioned, descended from insect-fertilized plants. In many water plants 
we find that (as in Ruppia) the flowers are borne up by long stalks 
until they reach the surface of the water, when the staminate flowers 
seatter their pollen which is blown by the wind on to the stigmas of 
the pistillate flowers. As soon as these are fertilized, their stalks 
begin to twist in a corkscrew fashion by which they are drawn down 
nearly to the bottom. Here the fruit matures, and the seeds are 
scattered. A still more singular contrivance is exhibited by 
“allisneria spiralis, a European water-weed. The plants are dicecious 
but grow close together. The pistillate flowers are produced on long 
stalks like those of Ruppia, and float on the surface of the water. The 
staminate flowers are on short stalks at the bottom of the water, but 
when mature they become detached and float to the surface where 
they open. Here they float about among the pistillate flowers, on to 
the stigmas of which their anthers project their pollen with a jerk. 
After fertilization, the stalk of the pistillate flower contracts spirally, 
and the ovary descends to the bottom of the water to ripen its seeds. 
The greatest degradation we know of however—as far as structure 
is concerned—is reached by the curious plants termed Sea- 
wracks or Zostera, a species of which we are familiar with, 
growing like a grass on the sandbanks in our harbour. In 
this plant both kinds of flowers are produced inside a water-tight 
sac made of the folded blades of the flattened stem. The male 
flowers consist of a single anther, and these are placed alternately 
with the female flowers, each of which consists of a single pistil. All 
trace of sepals and petals has been lost. The flowers can never be 
said to open, for their sac remains closed until fertilization has taken 
place, when the fruit begins to form and gradually the sheath decays. 
{t must have taken a considerable time too for a plant to have become 
so modified as to grow in (and at the bottom of) sea water. 
Another peculiar type of degeneration is shown among a number 
of New Zealand plants and particularly among such as are of ant- 
arctic distribution. I have already referred to the genus Colobanthus 
as a genus of degenerate chickweeds, and many similar cases might 
be adduced. Among Composites, the very fact of the flowers being 
so densely crowded together, shows that they have thus became 
ageregated to ensure their being seen by insects. But among some 
of our Composites, ¢.g., Abrotanella, Cotula, &c., which are chiefly 
found either on our mountains or in the cold bleak islands lying far 
