8.  Resedaceae.—­Reseda lutea.

Seeds collected from wild plants growing in this neighbourhood were sown in the kitchen-garden; and several of the seedlings thus raised were covered with a net.  Of these, some were found (as will hereafter be more fully described) to be absolutely sterile when left to fertilise themselves spontaneously, although plenty of pollen fell on their stigmas; and they were equally sterile when artificially and repeatedly fertilised with their own pollen; whilst other plants produced a few spontaneously self-fertilised capsules.  The remaining plants were left uncovered, and as pollen was carried from plant to plant by the hive and humble-bees which incessantly visit the flowers, they produced an abundance of capsules.  Of the necessity of pollen being carried from one plant to another, I had ample evidence in the case of this species and of R. odorata; for those plants, which set no seeds or very few as long as they were protected from insects, became loaded with capsules immediately that they were uncovered.

Seeds from the flowers spontaneously self-fertilised under the net, and from flowers naturally crossed by the bees, were sown on opposite sides of five large pots.  The seedlings were thinned as soon as they appeared above ground, so that an equal number were left on the two sides.  After a time the pots were plunged into the open ground.  The same number of plants of crossed and self-fertilised parentage were measured up to the summits of their flower-stems, with the result given in Table 4/35.  Those which did not produce flower-stems were not measured.

Table 4/35.  Reseda lutea, in pots.

Heights of plants to the summits of the flower-stems measured in inches.

Column 1:  Number (Name) of Pot.

Column 2:  Crossed Plants.

Column 3:  Self-fertilised Plants.

Pot 1 :  21 :  12 7/8. 
Pot 1 :  14 2/8 :  16. 
Pot 1 :  19 1/8 :  11 7/8. 
Pot 1 :  7 :  15 2/8. 
Pot 1 :  15 1/8 :  19 1/8.

Pot 2 :  20 4/8 :  12 4/8. 
Pot 2 :  17 3/8 :  16 2/8. 
Pot 2 :  23 7/8 :  16 2/8. 
Pot 2 :  17 1/8 :  13 3/8. 
Pot 2 :  20 6/8 :  13 5/8.

Pot 3 :  16 1/8 :  14 4/8. 
Pot 3 :  17 6/8 :  19 4/8. 
Pot 3 :  16 2/8 :  20 7/8. 
Pot 3 :  10 :  7 7/8. 
Pot 3 :  10 :  17 6/8.

Pot 4 :  22 1/8 :  9. 
Pot 4 :  19 :  11 4/8. 
Pot 4 :  18 7/8 :  11. 
Pot 4 :  16 4/8 :  16. 
Pot 4 :  19 2/8 :  16 3/8.

Pot 5 :  25 2/8 :  14 6/8. 
Pot 5 :  22 :  16. 
Pot 5 :  8 6/8 :  14 3/8. 
Pot 5 :  14 2/8 :  14 2/8.

Total :  412.25 :  350.86.

The average height of the twenty-four crossed plants is here 17.17 inches, and that of the same number of self-fertilised plants 14.61; or as 100 to 85.  Of the crossed plants all but five flowered, whilst several of the self-fertilised did not do so.  The above pairs, whilst still in flower, but with some capsules already formed, were afterwards cut down and weighed.  The crossed weighed 90.5 ounces; and an equal number of the self-fertilised only 19 ounces, or as 100 to 21; and this is an astonishing difference.