[82]

Sept 14th

Phalaris Left Hand

Phalaris Celery Heliotropism Obscure light

Fig 2.

Sept 14th 1878

[83]

Celery Heliotropism obscure light

Phalaris

Phalaris Right Hand

Fig I

[84]

Sept 14th

[84v]

106

Ipomœa

produced by the crossed flowers on the crossed plants were not always heavier than the self-fertilised seeds on the self-fertilised plants. The lighter seeds, whether produced in the one way or the other from crossed or self-fertilised flowers generally germinated before the heavier seeds. I may add that the crossed plants with very few exceptions flowered before their self-fertilised opponents, as might have been expected from their greater height and vigour.

The impaired fertility of the self-fertilised plants is shown in another way namely by their anthers being smaller than those in the flowers on the crossed plants. This was first observed in the seventh generation, but may have occurred earlier. Several anthers from flowers on the crossed and self-fertilised plants of the eighth generation were compared under the microscope; and those from the former were generally longer and plainly broader than the anthers of the self-fertilised plants. The quantity of pollen contained by one of the latter was, as far as could be judged by the eye, about

[Cross and self fertilisation, pp. 58-9: "The seeds produced by the crossed flowers on the crossed plants were not always heavier than the self-fertilised seeds on the self-fertilised plants. The lighter seeds, whether produced from crossed or self-fertilised flowers, generally germinated before the heavier seeds. I may add that the crossed plants, with very few exceptions, flowered before their self-fertilised opponents, as might have been expected from their greater height and vigour.
The impaired fertility of the self-fertilised plants was shown in another way, namely, by their anthers being smaller than those in the flowers on the crossed plants. This was first observed in the seventh generation, but may have occurred earlier. Several anthers from flowers on the crossed and self-fertilised plants of the eighth generation were compared under the microscope; and those from the former were generally longer and plainly broader than the anthers of the self-fertilised plants. The quantity of pollen contained in one of the latter was, as far as could be judged by the eye, about half of that contained in one from a crossed plant."]