370 Transactions. — Botany. 



hbourhood 



of the "West Coast road, a species which, as far as microscopic examination has 

 hitherto shown, is Hcematococcus sanguineus. 



This plant, forming blood-red spots upon the wool, consists of globular 

 cells, invisible to the naked eye. Viewed under the microscope, the globules 

 exhibit a golden-yellow colour, whilst the fibres of the wool are scarlet-red. 

 This colour without doubt is derived from the red pigment of the cells, which 

 has been pressed out from some cause impregnating the fibres. 



The portion of the wool which was not exposed directly to the light has a 

 green appearance, and this colour is most probably of the same origin as the 

 red. 



An analogous example of the change of colours is furnished by the plant 

 which forms the so-called "red snow" mentioned above. Whilst the contents 

 of the cells in a certain stage of their development are purple red, they change 

 to a green colour in another ; and one of the Algse which imparts to the 

 surface of the water a blood-red appearance, exhibits this colour only when 

 subjected to the direct rays of the sun ; the higher the light, the more intense 

 the colour appears. At other times the plant is green. 



A specimen of wool (sent to the Canterbury Museum by Messrs. Studholme 



Brothers), showing a green-colour and taken from a living sheep, was shown 

 to me by Dr. Haast, but this may be due to some infiltration of some mineral 

 colour, although it has all the appearance of having been produced by a similar 

 cause. It is true that all the fibres are uniformly coloured, but the Algse 

 originally growing amongst the wool may have been destroyed, leaving only 

 the traces of their former existence in the fibres of the wool. It is desirable 

 that further specimens presenting this uncommon appearance should be col- 

 lected by persons having the opportunity of doing so. 



Plate XXIV. — Fig. 1, Fibres of wool and Alga magnified. 2, Alga still 

 more magnified. 



Art. INI.— On some of the Naturalized Plants of Otago. By G. M. Thomson. 



[Bead before the Otago Institute, 1th April, 1874.] 



Mr. Kirk has recently called my attention to the fact that no list has yet 

 been drawn up of the naturalized plants either of Dunedin or Otago. It is to 

 be regretted that steps have not been taken, ere this, to watch and record the 

 introduction of all foreign plants, as otherwise it becomes in course of time 

 almost a matter of impossibility, on finding a plant of cosmopolitan distribution, 

 to say, with any degree of certainty, whether it is indigenous or not. We have 

 lately had experience of this difficulty, in the case of one of the commonest of 

 weeds — Polygonum aviculare — which has given rise to so much discussion 



