ACORNS 5^ 



from the seed becomes great, and we arrive at cases where 

 Nature seems to have abandoned the attempt, and, as in the 

 Oak and Horse Chestnut, the cotyledons never quit the 

 seed ; while those of the Walnut never quit the shell." 



In the Acorn the embryo radicle and plumule are con- 

 tained near the apex of the seed, as in the Hazel Nut and 

 other seeds of similar shape. Very shortly after germina- 

 tion has commenced they can be seen, if the seed is cut open, 

 with the unaided eye and present the following appearance : 



The outer ellipse being the stalks or beginning of the 

 cotyledons which do not in the least suggest having anything 

 to do with leaves. To this ellipse I shall hereafter refer 

 as the collar. And here let me remark that the first sign 

 of germination, of life, is not the rupture of the seed coat 

 but the visibility of the embryo ; some growth having 

 invariably taken place before it can be plainly discerned. 



From the time of the first sowing in the open ground and 

 certainly before the rupture of the inner membraneous coating, 

 the seed substance is positively charged. 



We can foresee what will happen when the seed is stimu- 

 lated into life. The embryo radicle will rupture the inner 

 membrane and take a downward course, the plumule will 

 grow upwards — both still adherent to the seed — and in due 

 course the first leaves will peep above the soil and come 

 for the first time into contact with light, though not for the 

 first time with oxygen. We may therefore usefully ponder 

 (1) How after the loss of electrostatic capacity is the elec- 

 trical system of the seedling maintained ? (2) In what 

 manner is it protected against possibly injurious light- 

 frequencies ? (3) How is it provided with oxygen ? and 

 (4) What is the probable function of chlorophyll ? 



We need not attempt to answer those questions in the 

 order in which they are asked, but will endeavour to deal 



