34 DR. EDWARD SCHUNCK ON THE 



yellowish hue of the oak, and the pure green of the beech 

 and larch relieving the sombre colour of the fir tree and 

 the yew, affords one of the most pleasing sights of that 

 delighful season. In early summer the young shoots of 

 some trees, such as the oak, the sycamore, and the thorn, 

 as well as the young leaves near the summit of each shoot, 

 are tinged of a lively red, passing by degrees into the green 

 of the mature leaves. The fruit -wings of the sycamore 

 are for many weeks in the summer similarly tinted ; and 

 the effect of the pink blush gradually shading off into the 

 pale green of the wing-tips is one that painters might in- 

 troduce with advantage into their pictures of still life. 

 This red colour is said to be due to erythrophyll, the 

 colouring-matter formed in some leaves in the autumn ; but 

 whether the substance is in both cases really the same may 

 be doubted. At the height of summer the foliage of trees 

 displays a uniform green tint of varying depth ; but it is 

 probable that at this season the chlorophyll has already 

 undergone a change, and I suspect that the sombre green 

 of some leaves (such as those of the elm) in summer is 

 partly due to a product of decomposition called " modified 

 chlorophyll/" which yields solutions of a much less lively 

 colour than the chlorophyll from which it is formed. 



The summer stage is succeeded by that of the autumnal 

 fading of foliage, a change so often observed that it needs 

 no description. With the exaggeration so often employed 

 when coloured objects are referred to, people frequently 

 speak of the multitudinous tints of autumn. In reality, 

 however, these colours, not counting the original green, 

 are only four in number, viz. yellow, brown, red, and 

 purple ; and of these the last is a dull inconspicuous colour, 

 while red occurs so seldom in our native trees as to add 

 but little to the total effect when our woods and plantations 

 appear in their autumnal clothing. It is to the passing of 



