380 MEANS OF CROSS-FERTILISATION. CHAP. X 



nearer.* But the most striking case which has been re- 

 corded is that by M. Godron,f who shows by the nature 

 of the hybrids produced that Primula grandiflora must 

 have been crossed with pollen brought by bees from 

 P. offieinalis, growing at the distance of above two 

 kilometres, or of about one English mile and a quarter. 

 All those who have long attended to hybridisation, 

 insist in the strongest terms on the liability of castrated 

 flowers to be fertilised by pollen brought from distant 

 plants of the same species.^ The following case shows 

 this in the clearest manner : Gartner, before he had 

 gained much experience, castrated and fertilised 520 

 flowers on various species with pollen of other genera 

 or other species, but left them unprotected ; for, as he 

 says, he thought it a laughable idea that pollen should 

 be brought from flowers of the same species, none of 

 which grew nearer than between 500 and 600 yards. 

 The result was that 289 of these 520 flowers yielded no 

 seed, or none that germinated ; the seed of 29 flowers 

 produced hybrids, such as might have been expected 

 from the nature of the pollen employed ; and lastly, 

 the seed of the remaining 202 flowers produced per- 



* Mr. W. C. Marshall caught in his ' Bastarderzeugung,' 1849, 



no less than seven specimens of a p. 670 ; and ' Kenntniss der Be- 



moth (Oucullia umbratica) with fruchtung,' 1844, pp. 510, 573. 



the pollinia of the butter fly-orcL is Also Lecoq, ' De la Fecondation,' 



(Habenaria chlorantha') sticking &c., 1845, p. 27. Some statements 



to their eyes, and, therefore, in have been published during late 



the proper position for fertilising years of the extraordinary ten- 



the flowers of this species, on an etency of hybrid plants to revert 



island in Derwentwater, at the to their parent forms ; but as it is 



distance of half a mile from any not said how the flowers were 



place where this plant grew : protected from insects, it may be 



' Nature,' 1872, p. 393. suspected that they were often 



t 'Kevue des Sc. Nat.' 1875, fertilised with pollen brought 



p. 331. from a distance from the parent- 



J See, for instance, the remarks species. 



by Herbert, ' Amaryllidaoese,' ' Kenntniss der Befruchtung, 



1837, p. 349. Also Gartner's pp. 539, 550, 575, 576. 

 strong expressions on this subject 



