314 Transactions.— Botany. 
the gorges of the Southern Alps, we also find the latter plant ; but I doubt 
whether this evidence alone would satisfy Mr. Kirk that it is not a modified 
descendant of some form of Brassica originally introduced by Cook. 
But in addition to the foregoing evidence I call Mr. Kirk’s attention to 
the case of the Chatham Islands, Ever since 1836 these islands have been 
visited by whaling ships, hailing during the earlier years exclusively from 
Hobart Town. In the year 1854 several vessels from Melbourne and Sydney, 
freighted with horses and cattle, went down to those islands, making very 
profitable trade with the Maoris who then occupied them, the trade being 
chiefly in potatos, then in good demand at the several diggings. For one 
entire horse the Maoris paid £250, whilst they gave correspondingly good 
prices for the other animals. Now soon after this trade began a considerable 
number of common English weeds, and amongst them Polygonum aviculare, 
made their appearance on the islands. These facts are given on the authority 
of Mr. Hunt and others who have long resided there, and have had ample 
opportunities of observing them, and they are quite analogous to those which 
I have mentioned above as applying to New Zealand. 
I do not think it necessary to follow Mr. Kirk in his criticisms upon the 
value of the Maori evidence in favour of the exotic origin of the plants in 
question, but I think I could satisfy him that such evidence is of more value 
when obtained from southern natives than if obtained from natives in the 
north. 
I cannot, moreover, close these observations without mentioning what 
will probably interest and surprise Mr. Kirk, namely, that I have always 
considered Azolla rubra as a foreign plant. I remember perfectly noticing its 
first appearance in Nelson, and it was then looked upon as having been 
brought from Tasmania with many other introductions of a more unsatisfactory 
character. 
Nore.—22nd February, 1873. Since the foregoing paper was read I have 
seen Mr. Kirk’s reply to my observations (see Art. XL.), but, in reference to 
Anderson’s mention of a knot-grass, it appears to me that Mr. Kirk has 
overlooked the fact that Polygonwm decipiens was collected by Banks and 
Solander, and would no doubt have been called a knot-grass by Anderson.— 
W. T. L. TRAVERS. 
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