128 HYBRIDISING AND CROSS-BREEDING. 



p. 1 6 1, the following translation of Gaertner's observations on 

 this subject is given : " When the stigma is dusted at the 

 same time or within certain limits with its own pollen in suffi- 

 cient quantity and that of some other species, the latter is 

 wholly inert, and the result is plants not differing in any 

 respect from the matrix : nor is the effect different if a division 

 or portion of the stigma be dusted with either pollen separately, 

 precaution being taken that there shall be no possibility of 

 admixture. The elective affinity (see page 119) for the natural 

 pollen makes the other completely negative. The result is 

 perfectly analogous when more than one kind of strange pollen 

 is applied, the native pollen being completely excluded. One 

 typical form alone results the effect of the impregnation of 

 that pollen for which the stigma has the greater elective 

 affinity." The late Dean Herbert (see Herb. Am. p. 375) 

 attempted to fecundate Calceolaria plantaginea with the pollen 

 of twelve other species industriously mixed together ; but very 

 few seeds ripened, and the result differed but little from seed- 

 lings obtained by fertilising with one kind of pollen. He 

 further remarks that in Crinum he has obtained mule and 

 natural seed from the same capsule ; and where there are three 

 distinct stigmas, as in Passiflora, it would be interesting to 

 fertilise each very carefully with pollen from three other species 

 and note the result : indeed, the glimmerings of successful 

 superfoetation which now and then appear seem to beckon 

 the hybridiser onwards, and suggest a careful series of varied 

 experiments. In cases where mixed pollen is used, the number 

 of seeds is generally small. Gaertner, however, relates a curious 

 exceptional instance : "A plant of Lychnis diurna was dusted 

 with pollen of Silene noctiftora. Twelve capsules of different 

 degrees of perfection were set, which yielded from twenty to 

 eighty seeds. The plants produced by them were, with two 

 exceptions, true L. diurna; but these had smaller leaves, a 

 more vigorous growth, and stronger but more finely divided 

 branches. It is possible that the main crop was due to the 

 presence of stamens in the Lychnis, which is not always strictly 

 dioecious, the two abnormal forms being due to the hybrid 

 fecundation. The experiment was repeated, but did not suc- 

 ceed. Mr Herbert has occasionally observed, in the case of 

 multilocular capsules, hybrid and natural seeds in the same 

 plant. Such cases are, however, of extreme rarity." 



The mode of experiment may be varied by dusting the 

 stigma at different intervals with the different kinds of pollen. 

 It is clear, however, that the strange pollen must be applied 

 first, to have in general any effect on the result. If impregna- 



