sect, ix.] INTRODUCTION. 47 



handsomer plant altogether." In seedlings from the orange or yellow 

 form grown in separate beds the proportion of seedlings true to their 

 parent colour would not be nearer than about 60 or 70 per cent., but 

 in the case of the white form Miss Jekyll considers that 95 per cent, 

 may be expected to come true. 



The yellow Horned Poppy (Glaucium luteum) is normally of a 

 lemon yellow very like that of P. nudicaule. Of this species also there 

 is an orange cultivated variety. The varieties of the tomato offer a 

 similar series of colour-variations. 



3. Fruits of many kinds are known in red and yellow forms. 

 For instance the yellow berried Yew is well known. It is described 

 under the name Taxus baccata fructu-luteo, Loud. "It appears to 

 have been discovered about 1817 by Mr Whitlaw of Dublin, growing 

 in the demesne of the Bishop of Kildare, near Glasnevin; but it 

 appears to have been neglected till 1833 when Miss Blackwood dis- 

 covered a tree of it in Clontarf churchyard near Dublin. Mr Mackay 

 on looking for this tree in 1837 found no tree in the churchyard, but 

 several in the grounds of Clontarf Castle, and one, a large one, with its 

 branches overhanging the churchyard, from which he sent us specimens. 

 The tree does not differ, either in its shape or foliage, from the common 

 yew, but when covered with its berries it forms a very beautiful 

 object, especially when contrasted with yew trees covered with berries 

 of the usual coral colour." Loudon, Arb. et Frut. Brit., iv. 1838, 

 p. 2068. 



I. The Raspberry (Rubus idceus) is another fruit which is known 

 wild in both the red and yellow forms, though the latter is less common. 

 According to Babingtox, it has pale prickles, and leaflets rather obovate. 

 Brit. Rubi, p. 13. (See Rivers, Gard. Ghron., 1867, p. 516.) 



Any person who has opportunities of handling animals and 

 plants in numbers can add many similar cases. These few are 

 taken more or less at random, as illustrations of the frequency 

 with which red, orange, and yellow may vary to each other. It is 

 of course not necessary to say that in numerous instances both 

 among animals and plants, the same parts which in one species 

 are yellow, in an allied species or in a geographically distinct race 

 are represented by orange or by red. To an appreciation of the 

 rapidity with which such changes may have come about, facts like 

 the foregoing contribute. 



The frequency of such variations suggest that many of these 

 yellow and red pigments are either closely allied bodies or different 

 forms of the same body. Until the chemistry of these substances 

 has been properly investigated nothing can be definitely stated 

 as to this, but the fact that vegetable yellows are very sensitive to 

 reagents is familiar. The lemon variety of the Iceland Poppy 

 treated with ammonia turns to a colour almost identical with 

 that of the orange variety, while the white variety so treated goes 

 primrose yellow. The lemon variety when boiled, or treated with 

 alcohol yields an orange solution, which is of the same tint. This 

 returns to lemon-colour if treated with ammonia or acids. The 



