152 HETEROSTYLED TREVIORPHIC PLANTS. CHAP. IV 



ones even more sterile than they otherwise would have 

 been. I have seen striking instances of this fact in 

 making illegitimate and legitimate unions with Pri- 

 mula ; and it is well known that the conditions of life 

 must be highly favourable to give any chance of suc- 

 cess in producing hybrids between species which are 

 crossed with difficulty. 



TABLE VS. Long-styled Form. 



I. 



Legitimate union. 

 13 flowers fertilised by the longest 

 stamens of the mid-styled. These 

 stamens equal in length the pistil 

 of the long-styled. 



Product of good seed in each cap- 

 sule. 



36 53 



81 



















45 



41 



38 per cent, of these flowers 

 yielded capsules. Each capsule con- 

 tained, on an average, 51*2 seeds. 



II. 



Legitimate union. 

 13 flowers fertilised by the longest 

 stamens of the short-styled. These 

 stamens equal in length the pistil 

 of the long-styled. 



Product of good seed in each cap- 

 sule. 



159 104 



43 119 



96 poor seed. 96 



103 99 



131 



116 



114 



84 per cent, of these flowers 

 yielded capsules. Each capsule con- 

 tained, on an average, 107*3 seeds. 



III. 



Illegitimate union. 

 14 flowers fertilised by the short- 

 est stamens of the mid-styled. 



3 

























 



Too sterile for any average. 



IV. 



Illegitimate union. 

 12 flowers fertilised by the mid 

 length stamens of the short-styled. 



20 





















 



Too sterile for any average. 



