FERTILISATION OF RED CLOVER. 503 
nection with this branch of the subject I should like to point out 
that the hive bee visits many flowers which are indisputably self- 
fertilising, such as the sorrel Ramex acetosella, Cerastium vulga- 
tum, Stellaria media, and many others, evidently obtaining much 
honey from them. Indeed, there is, I think, no doubt that the 
bee has a strong preference for flowers of quiet colour, well 
knowing that these contain more honey than those with gaudy 
hues ; and pale coloured flowers are usually self-fertilising. As 
Darwin has proved that cross fertilisation generally—not invari- 
ably—results in a benefit to the plants, or rather to the progeny 
of the plants so crossed, it appears that the functions of the hive 
bee in connection with fertilisation are more for the purpose of 
crossing (and consequently of improving) the races of plants, 
which, without the aid of these insects, would otherwise cross 
themselves, and bring about that weakening of constitution which 
certainly results from in-and-in-breeding, than for crossing self- 
sterile species. True, the Rev. G. Henslow has attempted to 
prove—in a very able article in the “ Linnzean Trans.” for 1879 
—that self-fertilisation is not injurious; and in support of this 
he brings forward the well-known facts that British self-fertilis- 
ing plants, introduced by man’s agency into this Colony and 
Australia, are more luxuriant and more fertile than in their 
native country. Now, it appears to me that the facts connected 
with the naturalisation of British plants in this Colony tend to 
support Darwin’s views as to the benefits derived from inter- 
crossing, for it must not be forgotten that, in this and all other 
new countries, there is constantly going on an extensive importa- 
tion of seeds from Europe and America, belonging to races which 
must be far removed in pedigree from those of the same species 
already in the country. As nearly all self-fertile plants are liable 
‘to be crossed either by the wind or by insect agency, there is every 
reason to believe that the races of species already in the country 
are crossed with those newly imported, and in consequence show 
an increased vigour of growth and greater fertility of seed pro- 
duction. If this theory be the right one, we may, of course, 
expect that in course of time, as the farmers and seed merchants 
give up the importation of stocks of seeds from England and 
America, and consequently check the importation of weeds, there 
will be a diminution of fertility and a lessening of the luxuriance 
of growth, which is such a marked feature in the naturalised 
plants of New Zealand. In confirmation of this view I have 
observed that the above-mentioned luxuriance of growth is most 
noteworthy in plants of short duration, in those, in fact, which 
have had time to produce several generations in the Colony. In 
the tree and shrub classes the luxuriance is not so marked, pro- 
bably because there has not yet been time, except in a few cases, 
for seedlings to be reared from colonially-produced seeds. On 
the other hand, it cannot be disputed that after a time the 
naturalised plants show some diminution of luxuriance, though 
not a very marked one as yet. 
In conclusion, I think that we may safely assume that the 
