156 ARTIFICIAL FERTILISATION 



is therefore a mathematical necessity that the pollen-cells must 

 have just the same part in the act of generation as the ovules." 

 And, based mainly on this doctrine, he follows up and amplifies 

 it in a series of aphorisms which, he admits, are to be " con- 

 sidered conjectural, and require to be submitted to proof," an 

 admission for which he is to be commended, and all the more 

 if he submitted to the like test the dogma on which they 

 mainly rest. It humbly appears to me that his statement had 

 been suggested from his experience among the Salices of all 

 plants the most mongrel in a state of nature. Now, in all this, 

 Wichura appears to me to imply that if a distinct intermediate 

 may be formed, and is formed, by crossing A on B, so may an 

 exactly similar intermediate be reciprocated by crossing B on 

 A. And M. Naudin, in his experiments among the Daturas, 

 enunciates the same belief, and holds " that there is not a sen- 

 sible difference between reciprocal hybrids of two species." 

 That distinguished observer, like Wichura, seems to have 

 confined his experiments to herbaceous or soft-wooded plants. 

 But, from a long and large experience among both hard and 

 soft wooded plants, I demur, ist, to the capability of the 

 parents being in all cases made subject to such reciprocity; 

 and, 2d, to the statement where such reciprocity does hold, 

 that the progeny are perfectly alike, whether A or B supply the 

 pollen. 



In my various crossings I have experimented on many hard 

 as well as soft wooded genera in particular, I would here 

 instance among the former the species of Rhododendron. In 

 these I have again and again been baffled to reciprocate a cross 

 which on one side was comparatively easy to be effected. 

 When the lovely and fragrant Rhododendron Edgeuwrthii first 

 bloomed in this country, all were eager to see its beauty and 

 perfume transfused into dwarfer and hardier forms. Some 

 tried the cross by making R. Edgeworthii the female or seed- 

 bearer, others by making it the male. I tried it in both ways, 

 but all my efforts failed where I attempted the cross on the R. 

 Edgeworthii. But while it would not be brought to bear hybrid 

 seed, I had no great difficulty in effecting a cross from its pollen 

 on R. ciliatum, another of Dr Hooker's beautiful Sikkim species, 

 having all the desirable requisites of hardihood, dwarf habit, 

 and free-flowering tendency; and, singularly, just as I had 

 obtained and sent off blooms of this brood to lay before the 

 committee of the Horticultural Society of London, Messrs 

 Veitch, of Chelsea, anticipated me in having a plant of this 

 identical cross first exhibited before that committee, which is 

 now well known and generally cultivated under the name of 



