62 GERMINATION 



" The gum or resin is secreted by hairs, by glands, by 

 leaf -teeth, or by the general epidermis. The gum cells are 

 developed early, and are short-lived. 



" . . . The secretion may either be a gum, . . . 

 or a resin ; or both may be present together. The resin, 

 according to Hanstein, is generally secreted in the interior 

 of the cells, and oozes through the cell wall, while the 

 mucus is generally the product of the epidermis. The 

 properties and functions of the two are no doubt different. 

 Some plants secrete both, as, for instance, the Horse 

 Chestnut." 



Now, assuming light-energy to be of an electrical, or 

 partly of an electrical character, as I think we must assume 

 if we believe that optics is a branch of electricity, it 

 would appear to be necessary to afford the young leaves 

 Bome measure of protection other than that of colour ; to, 

 in fact, provide for their insulation from electrical energy of 

 too high an electromotive force. 



When a nut, such as a Hazel Nut, or a seed, such as a 

 Horse Chestnut, is cut in section and exposed to the sun, 

 it throws out a secretion of a lipoid nature on the cut 

 surfaces and also takes on a tinge of yellow or brown ; not 

 only shielding the injury from actinic rays but regaining 

 in some degree the insulation which had been interfered with, 

 just as many trees exude a gum when the bark is pierced. 

 There is a purpose, surely, in this and it is not unreasonable 

 to suppose that the purpose has some connection with 

 electrical energy as a danger to young plant life. 



As regards oxygen supply to the seedling before its first 

 leaves emerge from the soil, we can agree that it is present 

 to some extent in the soil and shall see later on how the 

 further supply is obtained. The other question will find 

 answer as we examine the seedling. 



With the exception of those grown in the open ground 

 the seeds about to be described were potted in 4-inch pots 

 and kept in a cool greenhouse. Some were potted with the 

 apex pointing downwards, some with it directed upwards, 

 while others were laid horizontally in the soil. 



