154 JOUKNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



set of cords which should contain the definite number of petals^ 

 stamens, &c., give rise to numerous branches ; then these branches, on 

 issuing from the floral receptacle, are clothed with tissue, thereby making 

 extra petals or stamens, &c., as the case may be, so that such a flower 

 is not the result of the fusion of two or more individuals, but is a single 

 flower with multifold parts. Such flowers are sometimes hereditary, as. 

 in the case of Tomatos, the Forget-me-not, known by the names- 

 'Victoria,' 'Jewell,' See., and the Foxglove, terminated by a campanulate 

 multifold blossom, which the late M. H. Yilmorin succeeded in fixing, to 

 the amount of 90 per cent.* 



Japanese Maples. — Mr. Wallace showed some forms of Acer poly- 

 moiyhum of Japan with variously cut leaves. The English Maple (Acer 

 campestrc) has five principal lobes, but in .4. Pennsylvanicuin of U.S^ 

 there are only three. This resembles the fossil leaves found at ffiningen, 

 of the Miocene epoch, called A. trilohatum. The lobes were only serrated at 

 the margins, not deeply toothed. Its fruit was very small, and not 

 unlike that of A. rubrum of North America. In A. Pseud oplatanus 

 there is a tendency to separate a lower pair of lobes from the others^ 

 This species, called the Sycamore Maple, is often attacked by a fungus- 

 (Bhytisma accrimim), which makes large black spots on the leaf. It is- 

 interesting to find the fossil leaves similarly blotched by an allied fungus 

 called R. induratum. In Japan there are one or more species with single 

 unlobed leaves, as A. carjniiifoliwn and A. distijlum, &c. These repre- 

 sent the most primitive type of foliage. The three — and then the five — 

 and finally the many-lobed forms of A. lyolymorphum represent the line of 

 evolution in the genus Acer. Lastly, in the variety clissectiimdAlih^ 

 segments are quite distinct, making a truly compound palmate leaf ; while 

 in Ncgundo fraxinifoUa we also reach a perfectly compound but pinnate leaf- 



Pelargonium inquinans. — Mr. Cannell's magnificent collection of 

 Scarlet Geraniums, as they are improperly called, illustrated the vast 

 improvements made in the flower since 1714, when it was introduced 

 from C. G. H. The wild plant has a small scarlet flower, with petals 

 like windmill sails, ha\'ing great gaps between them ; whereas the present 

 plant has a flower with a perfectly circular outline. This is an attempt 

 at reversion to regularity, which all irregular flowers originally possessed ; 

 thereby approximating to a Geranium, which has a perfectly regular pen- 

 tamerous flower of five sepals, five petals, ten stamens in two whorls of five 

 each, and a pistil of five carpels. Five honey-glands are sjinmetrically 

 situated on the floral receptacle ; whereas in Pelargonium a long tube at 

 the posterior side of the flower, running down the stalk, contains the 

 honey. There are also only seven perfect stamens ; so that, under culti- 

 vation, the flower of a Pelargonium tends to reacquire the character of 

 Geranium, from which, or some similar form, it was probably descended. 



Trillium. — This genus, like our British wild flower Paris quadrifolia 

 and Arum maculatum, is remarkable for its net- veined leaves. If the 

 theory be true, that Monocotyledons, to which these genera belong, have 

 descended from aquatic Dicotyledons, the reticulated venation of Trillium, 

 &c.', may indicate a reversion or retention of an ancestral type of leaf. 



* Further details on this subject will be found in the following paper read before 

 the Scientific Committee of the Society. 



