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, bat 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. 



Note. — 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 Polygonum decijnens was collected by Banks and 

 Solandev, and would no doubt have been called a knot-grass by Anderson. — 

 W. T. L. Travers. 



