^90 GARTNER'S CONCLUSIONS. 



" The great fruitfulneas of many hybrid varieties is also a material 

 point as regards their useful qualities, especially in orchards and -vine- 

 yards, and where ornament, effect, or what the Germans call sesthetic 

 botany in its various branches is concerned, hybrids supply an endless 

 subject of experiment. 



"And lastly, the longer duration of many hybrids and their more 

 persistent larger blossoms make them especial objects of favour and 

 delight. 



" The great difficulty in the way of experiment is the frequent want 

 of fertility in the seeds of hybrids, and their tendency to wear out, 

 wherever there is a possibility of impregnation from neighbouring 

 varieties. 



" The simple hybrid reverts to the mother type by repeated impreg- 

 nation with the maternal pollen, or when the paternal pollen is applied, 

 goes forward to the type of the father : the conversion of the mother 

 into the father is, however, seldom synchronous with the contrary 

 change. Mootiana rustica was changed in. this manner by Kobeuter 

 into N. paniculata, and similar changes have been effected by others. 



"When hybrids are impregnated a third or fourth time with the 

 pollen of the original male parent, they gradually approximate more 

 and more to the male type, and at last are not distinguishable fi^om it, 

 except perhaps in a less degree of fertility, though this negative sign 

 vanishes sooner or later. There is no certainty as to the number of 

 successive impregnations necessary to produce this complete change. 

 Different species exhibit in this respect very different results. Mco- 

 tiana rustico-paniculata, even in the fifth degree, is occasionally com- 

 pletely sterile either as to the stigma or anthers, but especially aa 

 regards the latter. 



" The tendency of varieties to return to the maternal type seems to 

 be a peculiarity general to the vegetable kingdom, especially it left to 

 themselves, free from the trammels of cultivation. This return, how- 

 ever, in the second generation of simple hybrids, or of paternal mules of 

 the second degree, is always effected by fructification, and not by any 

 other mode of propagation. It seems also more easy than the approach 

 to the paternal type, though in neither case does it take place to a 

 considerable extent, nor does it take place in all genera, and when it 

 does occur the produce is less fertile." — Oesrtner. 



The following are ^ihs practical instructions for hybridising given by 

 Mr. Isaac Anderson, one of our most skilful operators in this way : — 



" To those who would attempt the hybridising or cross-breeding of 

 plants, I will now offer some suggestions for their guidance. It is an 

 essential element to success that the operator be possessed of indo- 

 mitable patience, watchfulness, and perseverance. Having determined 

 on the subjects on which he is to operate, if the plants are in the open 



