39 



and in less than a week the Ampelopsis became purple and 

 the Pelargonium red ! No red leaves appear on these plants 

 during the summer months, but an occasional leaf dying 

 from any cause simply turns yellow. The rationale of the 

 phenomenon would seem to be, that all the jilants being 

 somewhat chilled by the low temperature and dampness, the 

 older leaves of the central plants receiving the full power of 

 the morning sun, on account of their diminished vigor and 

 the check to the flow of sap, were unable to respond to the 

 demands of an active evaporation caused by a hot sun. 

 "The drying of the tissues is fatal to the component cells 

 And the organic contents speedily undergo decomposition," 

 and 1 may be permitted to add to the quotation : that new 

 colors result from the chemical changes set up. This 1 

 apprehend to be the explanation of the color change hi the 

 Ampelopsis and Pelargonium, and also of the effect of frost 

 as well as that of drought, and it will apply with equal cor- 

 rectness to some at least of the winter colors of evergreens 

 which will now be considered. One of our cultivated vines 

 which retains its leaves among the latest is the semi-ever- 

 green Lonicera Halleana or Japanese Honeysuckle. It may 

 be seen at times as late as Christmas, more or less variegated 

 with dull reds, reddish brown or yellowish colors, together 

 with much of the unchanged green foliage, presenting a 

 cheerful sight while most trees and shrubs are leafless. But 

 not every Lonicera is thus changed in color, for many a 

 trellis covered with this vine bears only green leaves. It 

 depends upon the exposure. A trellis serving the purpose 

 of a fence or screen covered on both sides with vines was 

 colored only on the sunny side, the other, more exposed to 

 the cold north winds, remained entirely green ; also similar 

 vines when on the north side of dw^ellings were found to be 

 green and when on the south they were colored ! 



Many of our native shrubs of an evergreen character are 

 similarly affected in the winter months: GauUheviu procum- 

 hens, Smilax glauca, Kalmia auguxtifolia and Ilex glabra on 



