different conditions.  The capsules produced by this cross contained, to my surprise, fewer and lighter seeds than did the capsules of the intercrossed plants; but this, I think, must have been accidental.  The seedlings raised from them I will call the “Colchester-crossed.”  The two lots of seeds, after germinating on sand, were planted in the usual manner on the opposite sides of five pots, and the remaining seeds, whether or not in a state of germination, were thickly sown on the opposite sides of a very large pot, Number 6 in Table 2/13.  In three of the six pots, after the young plants had twined a short way up their sticks, one of the Colchester-crossed plants was much taller than any one of the intercrossed plants on the opposite side of the same pot; and in the three other pots somewhat taller.  I should state that two of the Colchester-crossed plants in Pot 4, when about two-thirds grown, became much diseased, and were, together with their intercrossed opponents, rejected.  The remaining nineteen plants, when almost fully grown, were measured, with the following result: 

Table 2/13.  Ipomoea purpurea.

Heights of Plants in inches: 

Column 1:  Number (Name) of Pot.

Column 2:  Colchester-Crossed Plants.

Column 3:  Intercrossed Plants of the Tenth Generation.

Pot 1 :  87 :  78. 
Pot 1 :  87 4/8 :  68 4/8. 
Pot 1 :  85 1/8 :  94 4/8.

Pot 2 :  93 6/8 :  60. 
Pot 2 :  85 4/8 :  87 2/8. 
Pot 2 :  90 5/8 :  45 4/8.

Pot 3 :  84 2/8 :  70 1/8. 
Pot 3 :  92 4/8 :  81 6/8. 
Pot 3 :  85 :  86 2/8.

Pot 4 :  95 6/8 :  65 1/8.

Pot 5 :  90 4/8 :  85 6/8. 
Pot 5 :  86 6/8 :  63. 
Pot 5 :  84 :  62 6/8.

Pot 6 :  90 4/8 :  43 4/8. 
Pot 6 :  75 :  39 6/8. 
Pot 6 :  71 :  30 2/8. 
Pot 6 :  83 6/8 :  86. 
Pot 6 :  63 :  53. 
Pot 6 :  65 :  48 6/8. 
Crowded plants in a very large pot.

Total :  1596.50 :  1249.75.

In sixteen out of these nineteen pairs, the Colchester-crossed plant exceeded in height its intercrossed opponent.  The average height of the Colchester-crossed is 84.03 inches, and that of the intercrossed 65.78 inches; or as 100 to 78.  With respect to the fertility of the two lots, it was too troublesome to collect and count the capsules on all the plants; so I selected two of the best pots, 5 and 6, and in these the Colchester-crossed produced 269 mature and half-mature capsules, whilst an equal number of the intercrossed plants produced only 154 capsules; or as 100 to 57.  By weight the capsules from the Colchester-crossed plants were to those from the intercrossed plants as 100 to 51; so that the former probably contained a somewhat larger average number of seeds.]