1885.] NOTES OX BRITISH ORCHIDS. 49 



0. masmla can this variation of leaf be attributed to soil, altitude, 

 or situation, us all these I liave carefully studied in conjunction 

 M'ith the plants. In llic large patch of 0. mamlata referred to 

 above, nearly one-third of the plants were green-leaved, and grew 

 indiscriminately amongst the others, so that in tins case at least 

 soil could hardly be considered as the cause of difference. The 

 production of seed in 0. macidata is something amazing, one capsule 

 alone after careful compulation being estimated by Darwin to 

 contain no less than 6200 seeds, most of which were good; and as 

 there are often over 30 capsules on the same plant, the total number 

 would be 186,300. 



As showing the possible rate of increase of this orchid, and to 

 give an idea what the above figures really mean, we will sum up in 

 the words of Darwin: "An acre of land would hold 174,240 

 plants, each having a space of 6 inches square, and this would be 

 just sufficient for their growth ; so that, making the fair allowance 

 of 400 bad seeds in each capsule, an acre would be thickly clothed 

 by the progeny of a single plant. 



" At the same rate of increase, the grandchildren would cover a 

 space, slightly exceeding the island of Anglesey ; and the great- 

 grandchildren of a single plant would nearly (in the ratio of 47 to 

 50) clothe v/ith one uniform green carpet the entire surface of the 

 land throughout the globe." 



When we consider, therefore, on the one hand, the great produc- 

 tion of seed, and on the other, the comparative scarcity of the 

 plant, we are naturally led to ask the question, What checks the 

 unlimited multiplication of this orchid ? — a question which has as 

 yet never been satisfactorily answered. As an ornamental garden 

 plant, 0. maculata is very desirable, and when once thoroughly 

 established, will increase in size and splendour from year to year. 

 It may be planted in good, rich, rather damp loam, and when once 

 thoroughly established, should be left alone, for, like most of the 

 palmate tubered orchids, this plant is rather impatient of root 

 disturbance. 



A variety of the above, named 0. maculata superha, was distri- 

 buted by the late Miss Hope, of Wardie Lodge, Edinburgh, from 

 which circumstance the plant is usually known as Miss Hope's 

 orchid. It is a very handsome variety, of a strong, sturdy nature, 

 with stiff, almost erect leaves thickly covered with small purple spots. 

 The history of this plant I do not know, but if I remember rightly, 

 the Eev. C. Wolly Dod told me that it was ibund or rather detected 

 in a cottage garden at Kilmarnock, by Miss Hope, and whose name 

 it still bears. I have grown and flowered this plant very success- 

 fully from tubers kindly sent me by the late Eev. H. Harpur Crewe, 



