PDF - Wallace Online

TROPICAL NATUREpurple or blue, three -lilac,and two red or pink, showing avery similar proportion of white and yellow flowers to whatobtains farther south.We have, however, a remarkable flora in the southernhemisphere, which affords a crucial test of the theory of greaterintensity of light being the direct cause of brilliantly-colouredflowers. The Auckland and Campbell's islands, south of NewZealand, are in the same latitude as the middle and the southof England, and the summer days are therefore no longerthan with us. The climate, though cold, is very uniform,and the weather "very rainy and stormy." It is evident,then, that there can be no excess of sunshine above what wepossess, yet in a very limited flora there are a number offlowers which Sir Joseph Hooker states are equal inbrilliancy to those of the arctic flora. These consist ofbrilliant gentians, handsome veronicas, large and magnificentComposite with purple flowers, bright ranunculi, showyUmbelliferse, and the golden -flowered Chrysobactron Eossii,one of the finest of thelAsphodeleee. All these fine plants,it must be remembered, are peculiar to these islands, andhave therefore been developed under the climatal conditionsthat prevail there ;and as we have no reason to suppose thatthese conditions have undergone any recent change, we maybe quite sure that an excess of light has had nothing to dowith the development of these exceptionally bright and handsomeflowers. Unfortunately we have no information as tothe insects of these islands, but from their scarcity in NewZealand we can hardly expect them to be otherwise than veryscarce. There are, however, two species of honey -suckingbirds (Prosthemadera and Anthornis), as well as a smallwarbler (Myiomoira); and we may be pretty sure that theformer at least visit these large and handsome flowers, andso effect their fertilisation. The most abundant tree on theislands is a species of Metrosideros, and we know that treesof this genus are common in the Pacific islands, where theyare almost certainly fertilised by the same family of Meliphagidseor honey-sucking birds.1I have now concluded this sketch of the general pheno-Coloured figures of all these plants are given in the Flora Antarctica, vol. L