Hybridising 



( 431 ) 



Hydrangea 



of either parent over tlie other. .Sometimes the 

 influence of the one parent is so slight as to be 

 scarcely observable ; at other times the progeny 

 will favour one parent in, say, the form and 

 colour of the (lowers, and the other parent in 

 the habit of growth. 



Nor can any rule be expressed as to the prob- 

 ability or otherwise of two species fusing, unless it 

 be the sufficiently vague one that it is governed by 

 physiological affinity. Thus, species which are 

 apparently widely separated from each other will 

 cross quite readily, and others which are appar- 

 ently quite closely related to each other will 

 obstinately refuse to cross. The whole question 

 of sexual affinity is involved, and at present 

 much is more or less conjecture. 



The hybridist, however, is working upon strictly 

 scientific grounds. He does not hybridise for the 

 sake of hybridising, or merely at random ; and his 



to something else which could not be produced 

 without this now apparently useless connecting 

 link. 



HYDNUM. 



A large genus upwards of 200 species of 

 Fungi (iird. Hymenomycetes). They vary both 

 in size and general appearance, but they may all 

 be recognised by the prickle-like, spore-bearing 

 branches which protrude from the under side of 

 the cap or " pileus." They are common to almost 

 all climates and latitudes, but the temperate 

 regions contain the greatest number. The common 

 British species, repandum, is not only edible 

 but really delicious, although few people care to 

 touch it. Some up-to-date cooks make a capital 

 jmree of these Mushrooms, and they are also used, 

 like the common Agaric, to flavour stews. Hydnum 

 repandum may easily be told from other common 



Photo : Council <& Company, Ltd, 



HYDHANGEA ALTISSIMA (see p. 482). 



fiinfr'rre the cross breeder is equally exact. Each 

 has an ideal in view, and he selects the parent* of 

 the progeny with careful skill. Thus the micro- 

 scope is not infrequently called into play to 

 .-i-rrrt.-iin whether the grains of pollen from a 

 particular plant are plump, clean, and well shaped 

 before that plant is selected as the male parent,, 

 and if the pollen does not satisfy those conditions 

 the plant is discarded. It is well within the possi- 

 bilities of the future that the present system of 

 plant classification may give place to another 

 system under which they are grouped .according to 

 their inward affinities, and not so much their out- 

 ward resemblances. It is safe to say that the 

 liybridiser has done more than anyone else to 

 throw light upon this question of affinities. 



One curious instance of a bigeneric hybrid may 

 be cited in Philageria, a cross between tho climber 

 ]/,-i]> -igeria rosea and the shrubby 1'hilesia buxifolin. 

 its only congener. Philageria is to some extent 

 intermediate in character between the parents, 

 but, curiously enough, it is far less .-howy than 

 either of its parents, and from a horticultural point 

 of view is useless, except in so far as it m.iy lead 



Fungi by the curious way in which the "cap" is 

 set on one side turned up at the brim, as it were. 



HYDRANGEA. 



Description. Greenhouse or hardy, deciduous or 

 evergreen shrubs or trees (ord. Saxifrageae). Some 

 of the species, notably Hortensia and its varieties, 

 and paniculata hortensis (syn. paniculata grandi- 

 flora), are very largely grown both in pots and 

 outdoors. Hortensia is hardy only in the southern 

 portion of Jiritain, but there it will make huge 

 bashea, and flower with the greatest freedom. Pani- 

 ciilata hortensis is perfectly hardy. The flowers of 

 Hydrangeas are produced in large trusses (cymes, 

 corymbs, or panicles), and are remarkable by reason 

 of the number of sterile florets they produce. 

 These florets constitute the showy part of tho 

 flower, and it is towards increasing their number 

 and size that the aim of the cultivator is directed. 

 The flowers of Hydrangeas will last for many 

 weeks in condition, and ultimately they have to 

 be cut off when they have become green with age. 



Propagation. Uy cuttings. A common practice, 

 and one to !>; recommended, is to grow plants of 



