C. Pellrw and F. M. Durham Kil 



thniiii [nisiticin, ;i featuro of some interust in thu light ul' thu future 

 history of the phint. The h3-brid was . propagated vegetatively and 

 distributed by Messrs Veitch (PI. XXV, fig. 3). No viable seed was 

 obtained until about the year 1905, when a single plant bore seed. The 

 following description of this plant is given in the Gardeners' Chronicle, 

 Nov. 1911, p. 378: "This plant was, as we learn from Messrs Veitch, 

 remarkable in several ways. In the first place its main inflorescence 

 bore pin-eyed (long styled) flowers. In the second place, though the 

 style of the flowers was long, the stamens were in the position which 

 they occujjy in thrum-eyed flowers. In other words the flowers, though 

 ■pin-eyed as judging by their styles, were thrum-eyed as far as their 

 stamens were concerned. In the third place other inflorescences which 

 developed on this long styled plant bore ordinary thrum-eyed flowers. 

 Self-polliiuttion of the pin-eyed flowers resulted in the production of 

 good seed, from which have been raised all the fertile plants of 

 P. Keiuensis now in cultivation." 



We have little personal knowledge of this form. The tetraploid 

 type is abundant in cultivation, and on its introduction the dijiloid 

 gradually disappeared. Only recently have we been able, by the help 

 of Mr Coutts, to obtain a specimen which will be the subject of further 

 investigation. 



We have been informed by Mr Garrett and Mr Coutts of the Royal 

 Gardens, Kew, that the fertile Ketuensis thus obtained differed in 

 ajDpearance from the sterile hybrid. We will refer to these differences 

 later, but a more important difference was discovered by Miss Digby'. 

 She found that whereas P. verticillata, P. floribunda, and the sterile 

 hybrid have 18 chromosomes diploid number and 9 haploid number 

 the fertile hybrid has 3ti diploid and 18 haploid, being thus in the 

 condition now called tetraploid. Moreover Digby and Farmer have 

 since found that the chromosomes of the tetraploid are smaller than 

 those of the diploid form-. 



Both at Kew and at Messrs Veitch's nursery, the cross between 

 verticillata and floribunda was repeated ; experience showed that the 

 hybrid Kewensis is obtained very rarely, and that in the majority of 

 cases the offspring are so-called " maternal hybrids, ' i.e. they resemble 

 the female parent. 



Throughout this paper the term Kewensis, unless qualified, refers to 

 the tetraploid form. 



' L. Digby, .inn. Hut. Vol. xsvi. No. 102, April, l'.)12. 

 ■ Farmer and Digliy, Phil. Trans. R. S., B. 205, p. 1. 

 Jourii. o£ Geu. v 11 



