102 THE VICTOBIAN NATURALIST. 



tint. The intervenular space showed a peculiar spectrum, a spec- 

 trum including all its usual colours except blue, wherea.s in the 

 petals, under the ordinary colour, the spectrum appears complete. 

 Strange as this sounds, yet it is a fact. Afterwards the petals 

 assumed a very faint gray, almost tending to blue colour ; the 

 central portions became very slightly pink, increasing to almost a 

 violet tint, thus giving the flower a most soft and tender appear- 

 ance. Otherwise it differed not from the ordinary state. At 

 first I was led to think the described variability was chiefly due 

 to the difference in soil ; but I am now, after careful observation 

 and comparison of its regional distribution, convinced that this is 

 not the case, as the same phenomenon may be noticed on all 

 kinds of soils. Taking into consideration that temperature and 

 light have effect upon colour, I commenced a series of notes to 

 that effect. Purposely I planted, some time ago, a Swainsonia 

 procumbens in ray flower garden, so as to have a better oppor- 

 tunity to make notes about it. Comparing the one I have in my 

 garden with those growiu'? wild, I found them always to be alike 

 as regards the colour. This fact, then, would naturally point to 

 another cause, and this I think is solely a meteorological one. 

 I am fully aware to what danger I expose myself of being ridiculed 

 at this idea, but I shall try to explain. 



On sultry spring days the variability of the colours is the 

 greatest, increasing or decreasing in intensity according to the 

 temperature. When the sky is "overcast" and almost a calm 

 reigns, and indications are for a change, the petals of Swainsonia 

 procumbens are dark blue, the venules crimson with ramifications 

 of same colour at an acute angle. Should a north wind prevail, 

 the venules become blue and the petal violet in the centre, and 

 surrounded by prussian blue merging into light lilac, the 

 periphery being pale or rather grayish ; but whenever an electric 

 tension of the atmosphere is present, the longitudinal venules 

 become much broader, assume a much deeper colour, and affect 

 also the intermediate cells, the remainder becoming of brilliant 

 indigo. As soon as a discharge of the electric tension has taken 

 place, the colour again changes to its original state, but the 

 same process is repeated an almost indefinite number of times in 

 the same individual. 



This season I have experimented with this flower. I have 

 taken a newly but perfectly opened blossom, noted carefully its 

 colour in all its parts. Having done so, I cut off a small portion 

 of the petal and exposed the remainder to a strong electric cur- 

 rent. A change was noticed immediately, the longitudinal venules 

 appeared rose, and the central portion became deep blue. Cutting 

 a portion of this part, I placed both this and the piece I cut off 

 before into some hydrochloric acid for a few minutes, then mounted 

 them for miscroscopical examination. This examination shows 



