naceae 80, Polemoniaceae, Borraginaceae 81, Convolvulaceae 

 82, Solanaceae 83, Scrophulariaceae 84, Labiateae 87, Aristoi. 

 lochiaceag 92, Elaeagnaceae 93, TJrticaceae 94, Salicaceae 96, 

 Orchidaceae 97, Iridaceae 107, L iliaceae 108, Ar aceae , 113, 



CHAPTER VI. 



Flowees and theie unbidden guests: Perforation of 

 flowers 116, How flowers are protected 117. 



CHAPTER VII. , 



Cross and Self-Feeiilization of Plants: Cross-fertili- 

 zation 121, impotency 127, cucurbits 129, pears 130, superi- 

 ority of crossed plants, 131, self-pollination 132, cleistoga- 

 mous flowers 133, Autogamy and Alpine plants. Autogamy 

 in grasses 135, Cause for cleistogamy 136. 



chapter VIII. 



The eflfect of cross-fertilization in plants 139. 



CHAPTEE IX. 



Hybrids 146, parental characters 147, rose hybrids 150, 

 Apples 151, cucurbits 152, ternary hybrids 153, graft hy- 

 bridi 154, prepotency 153. 



