Column 2:  Crossed Plants.

Column 3:  Self-fertilised Plants.

Pot 1 :  96 :  73. 
Pot 1 :  86 :  78. 
Pot 1 :  69 :  29.

Pot 2 :  84 :  51. 
Pot 2 :  84 :  84. 
Pot 2 :  76 1/4 :  59.

Total :  495.25 :  374.00.

The average height of the six crossed plants is 82.54 inches, and that of the six self-fertilised plants 62.33 inches, or as 100 to 75.  Every crossed plant exceeded its antagonist in height.  In Pot 1 the middle plant on the crossed side was slightly injured whilst young by a blow, and was for a time beaten by its opponent, but ultimately recovered the usual superiority.  The crossed plants produced spontaneously a vast number more capsules than did the self-fertilised plants; and the capsules of the former contained on an average 3.37 seeds, whilst those of the latter contained only 3.0 per capsule, or as 100 to 89.  But looking only to the artificially fertilised capsules, those on the crossed plants again crossed contained on an average 4.46 seeds, whilst those on the self-fertilised plants again self-fertilised contained 4.77 seeds; so that the self-fertilised capsules were the more fertile of the two, and of this unusual fact I can offer no explanation.

Crossed and self-fertilised plants of the sixth generation.

These were raised in the usual manner, with the following result.  I should state that there were originally eight plants on each side; but as two of the self-fertilised became extremely unhealthy and never grew to near their full height, these as well as their opponents have been struck out of the list.  If they had been retained, they would have made the average height of the crossed plants unfairly greater than that of the self-fertilised.  I have acted in the same manner in a few other instances, when one of a pair plainly became very unhealthy.

Table 2/7.  Ipomoea purpurea (Sixth Generation).

Heights of Plants in inches: 

Column 1:  Number (Name) of Pot.

Column 2:  Crossed Plants.

Column 3:  Self-fertilised Plants.

Pot 1 :  93 :  50 1/2. 
Pot 1 :  91 :  65.

Pot 2 :  79 :  50. 
Pot 2 :  86 1/2 :  87. 
Pot 2 :  88 :  62.

Pot 3 :  87 1/2 :  64 1/2.

Total :  525 :  379.

The average height of the six crossed plants is here 87.5, and of the six self-fertilised plants 63.16, or as 100 to 72.  This large difference was chiefly due to most of the plants, especially the self-fertilised ones, having become unhealthy towards the close of their growth, and they were severely attacked by aphides.  From this cause nothing can be inferred with respect to their relative fertility.  In this generation we have the first instance of a self-fertilised plant