260 DR J. M. MACFARLANE ON THE 



The italics are mine, and my observations, repeatedly and carefully verified on a great 

 variety of material, are the opposite of his. 



Alike to acknowledge my indebtedness, and to help any who may wish in future to 

 compare the growths for themselves, I would mention the following sources from 

 which material has been drawn : — 



From the gardens of Hopetoun House, Mr Smith has kindly furnished repeated 

 supplies from three fine specimens growing in the shrubbery of the flower-garden close 

 to the brook. Mr Smith has watched the behaviour of these for me, and states that the 

 yellow and purple parts blossom nearly simultaneously, or the former has slightly the 

 advantage, while the mixed part opens several days later. Both parent branches pro- 

 duce abundant fruit, but he has never noticed a pod on the third. 



From Cowden Gardens, Dollar, Mr Nicolson has sent me two fine branches showing 

 the three types in bloom ; and similarly I am indebted to Mr Dow, gardener at New- 

 byth, Prestonkirk, and to Mr Fortune, Blairadam. The last-named informs me that 

 a very fine and large tree was blown down three years ago ; the young plant, 

 however, promises well. Dr Scott informs me that two good trees grow in his grounds 

 near Melrose, one also is in the garden of Mr Lyall at Newburgh, and another in 

 Dr G. Carnachan's garden at Clynder, Eoseneath. 



I have further received specimens of the yellow and intermediate types from Mr 

 Chapman, gardener to C. Jenner, Esq.. Duddingstone Lodge, from Mr Hunter, gardener 

 at Lauriston Castle, and from Mr Fairgrieve, of Dunkeld Palace Gardens. The trees 

 at Duddingstone Lodge have not as yet developed the purple form, if the germs of it 

 exist in the plants. The two specimens at Lauriston are specially noteworthy, since Mr 

 Smith informs me that he remembers having seen the three growing on adjoining branches. 

 The trees appear to have reached or passed their maximum of growth, and the purple 

 bunches have entirely disappeared now. Mr Fortune informs me that the purple tufts 

 frequently die away on one part of the tree and burst out in fresh regions ; and I have 

 noticed a less marked tendency in the intermediate or " Adami " part, so that the purple 

 portion is shortest lived, the intermediate longer, and the yellow is the most persistent. 

 A tree in the Edinburgh Botanic Garden produced the three so recently as seven 3^ears 

 ago, but no traces of the purple and red have appeared during 1890 and 1891. 



The Dunkeld tree is interesting, for the " Adami" flowers on it are completely double, 

 which is a rare occurrence among leguminous species. Mr Fairgrieve has watched for 

 me the flowering period of the yellow and intermediate parts, and he finds that the first 

 precedes the second by five days. 



Beside the above, many other trees appear to be scattered over the country, if we 

 may judge from gardening literature. The oldest that I have examined appears to be 

 from fifty to sixty years, if we may judge from specimens of the common Laburnum of 

 known age and size. 



In the following description, unless expressly stated otherwise, reference to C. Labur- 

 num and C. purpureus may apply either to the isolated parents, or to the parts of these 



