Aucust, 1909.] THE ORCHID REVIEW. 338 
against Darwin that he did not explain the origin of variation, and especially 
that he did not show how variations of sufficient moment to be selected for 
preservation in the struggle for existence have in the first place originated. 
A brief reply to the first objection was that variation is a common attribute 
of many natural substances of which living matter is only one, and to the 
second that Darwin described with special emphasis instances of what he 
terms correlated variability, which furnished the key to the explanation of 
what are called useless specific characters and incipient organs. That key 
consisted in the fact that a general physiological property or character of 
utility is often selected and perpetuated which carries with it distinct, even 
remote, correlated growths and peculiarities obvious to our eyes, yet having 
no functional value, though at a later stage in the history of such a form 
these correlated growths might acquire value and become the subject of 
selection. 
ORCHIDS BY COLOUR PHOTOGRAPHY. 
SomE of our readers are interested in the application of colour photography 
to Orchids, and we have now had the pleasure of seeing some examples 
taken by the new Lumiere process. 
Mr. G. Hirchfeldt Hansen, of Copenhagen, who recently paid a visit to 
England as a member of the International Congress of Applied Chemistry, 
showed us three very beautiful specimens of the art, one showing a plant of 
Phalzenopsis amabilis Rimestadiana, another of Cattleya intermedia, and a 
third a group of Orchids in the nursery of Mr. J. Waterspadt, Copenhagen. 
The colours were very faithfully rendered, and the third photograph 
mentioned formed a pretty severe test of the process, for it showed plants of 
Cattleya labiata, Lelia autumnalis, Lycaste Skinneri, Phalenopsis 
Schilleriana, P. amabilis Rimestadiana, and Paphiopedilum niveum, all 
within the limits of quarter plate size (4+ by 3} inches), so that the flowers 
were greatly reduced, but we were able to identify them all at once with a 
pocket lens of low power. Mr. Hansen says that the photographs come 
out well as lantern slides, which we can well understand, being both 
accurate in drawing and colouring. 
The others mentioned are two groups of Orchids taken by Mr. C. P. 
Raffill, of Kew, which are also very beautiful. The first group shows Cattleya 
Bowringiana, Leliocattleya Canhamiana, Oncidium varicosum Rogersii, 
Vanda ccerulea, Paphiopedilum Lawrenceanum (not in flower), and some 
foliage plants behind. The second group shows Cycnoches chlorochilon, 
Mormodes buccinator, M. badium, Catasetum tabulare, a quadridens and. 
C. x splendens. The details are necessarily very minute. The other 
subjects are a group of Chrysanthemums and scarlet Pelargoniums, and a 
lilac-coloured Crinum, the latter taken as large as the plate will allow. 
