MINUTE STRUCTURE OF PLANT HYBRIDS. 



241 



above, and exhibits slight transverse foldings, particularly on first opening of the flowers. 

 The teeth of the corolla are flat or very slightly recurved, while the colour is a very 

 delicate rose-pink, so that the plant has become a great favourite in gardens. The 

 corolla of 1 is tubular, slightly urceolate, transversely plicate round the contracted throat, 

 and has strong recurved teeth. The colour is a bright purple-pink. 



Microscopically the outer surfaces of the three are almost alike, but distinct differences 

 are observable internally. The epidermal cells of 3 are glabrous over their base and 

 upper parts, but about one-third up a zone of long, beautiful hairs grow out, which 

 correspond in position with similar ones on the bases of the filaments, and are evidently 

 formed as nectar covers. The cells of the base are greatly elongated, five to six times as 

 long as broad, but upwards they gradually widen, assume an irregular aspect, and have 

 wall infoldings. The epidermal cells of 1 are glabrous throughout, those at the base 

 about three times as long as wide, but higher up they widen out, have a sinuous outline, 

 and infoldings of the walls. In 2 the cells throughout are intermediate between those of 

 the parents, and, further, the hairs of 3 are prettily reproduced, of smaller size, reduced 

 number, and in the exact position. 



Stamens. — These are on the average T 7 F to ^ in. long, of a brown -black colour, 

 and the filaments have a dense circlet of long fine hairs like those on the corolla in 3. 

 In 2 they are ^ in. long, the anthers are of a black-red colour, and a circlet of hairs like 

 those of the last, though reduced in number and size, covers the bases of the filaments. In 

 1 the stamens are T \ in. long, the anthers are of a deep red colour, and the filaments 

 have a very few short hairs at their bases. The pollen grains of 3 are 40 fi across, of 1 

 they are 30 /a, and in both cases mature well. Those of 2 are 30 fx, at most, but they are 

 almost entirely bad, not more than one in twenty appearing as if capable of effecting 

 fertilisation. 



Pistil. — The pistil of 3 is at first short, but eventually, by continued elongation of 

 the style, it becomes T 9 ^ in. long, and is straight throughout. That of 1 is T ^ in. long, 

 the upper part of the style is curiously curved in knee-like fashion, first downwards and 

 then upwards. That of 2 is j\ in. long, and in most cases on first opening of the flower, 

 or during the whole blossoming period, is obliquely bent upwards, and then becomes 

 straight. The ovary of 3 is richly covered with long gland hairs like those of the sepals 

 and sparingly also with simple hairs ; the stigma is deeply five-cleft and 200 jjl across. In 1 

 the grooves between the carpels have short-stalked gland hairs, and a few short simple 

 hairs; the stigma is entire, slightly depressed in the middle, and 150 /x across. In 2 the 

 ovarian surface shows the two types of gland hair derived from the parents, along with a 

 few simple hairs; the stigma is deeply depressed or almost lobed, and measures 170 [x 

 across. 



The above description of Bryanthus erectus, and of its reputed parents, proves that 

 equally in naked-eye and histological characters the parents differ considerably from each 

 other, and that the hybrid inherits unblended peculiarities of both in hair appendages, 

 and general blending to an intermediate extent in the cells of the organism as a whole. 



1. Menziesia 



empetriformis, 

 var. 



2. Bryanthus 



erectus. 



3. Rhododendron 



Chant Eecistus. 



