CONTENTS. 



CHAPTER I. 



INTRODUCTOKY KKMARKS. 



Various means which favour or determine the cross-fertilisation a 

 plants Benefits derived from cross-fertilisation Self- fertilisa- 

 tion favourable to the propagation of the species Brief history 

 of the subject Object of tlie experiments, and the manner in 

 which they were tried Statistical value of the measurements 

 The experiments carried on during several successive genera- 

 tions Nature of the relationship of the plants in the later 

 generations Uniformity of the conditions to which the plants 

 were subjected Some apparent and some real causes of error 

 Amount of pollen employed Arrangement of the work 

 Importance of the conclusions Page 1-27 



CHAPTER II. 



CONVOLVULACE.. 



Ipomoea purpurea, comparison of the height and fertility of the 

 crossed and self- fertilised plants during ten successive genera- 

 tions Greater constitutional vigour of the crossed plants 

 The effects on the offspring of crossing different flowers on the 

 same plant, instead of crossing distinct individuals The 

 effects of a cross with a fresh stock The descendants of the 

 self-fertilised plant named Hero Summary on the growth, 

 vigour, and fertility of the successive crossed and self-fertilised 

 generations Small amount of pollen in the anthers of the self- 



