1886.] on the Forms of Seedlings. 519 



derations connected with the construction of the fruit. In reply to 

 this, he compared the seedlings of the sycamore and of the oak. In 

 the sycamore, the seed is more or less an oblate spheroid, and 

 the cotyledons, which are long and ribbon-like, being rolled up 

 into a ball fit it closely, the inner cotyledon being generally 

 somewhat shorter than the others. On the other hand, the nuts 

 of the beech are triangular. An arrangement like that of the 

 sycamore would therefore be utterly unsuitable, as it would neces- 

 sarily leave great gaps. The cotyledons, however, are folded up 

 somewhat like a fan, but with more comj^lication, and in such a 

 manner that they fit beautifully into the triangular nut. Can we 

 however, he said, carry the argument one stage further ? Why should 

 the seed of the sycamore be globular, and that of the beech triangular ? 

 Is it clear that the cotyledons are constituted so as to suit the seed ? 

 May it not be that it is the seed which is adapted to the cotyledons ? 

 In answer to this, we must examine the fruit, and we shall find that 

 in both cases the cavity of the fruit is approximately spherical. That 

 of the sycamore, however, is comparatively small, and contains one 

 seed, which more or less exactly conforms to the cavity in which it 

 lies. In the beech, on the contrary, the fruit is at least twice the 

 diameter, and contains from two to four nuts, which consequently, in 

 order to occupy the space, are compelled (to give a familiar illustra- 

 tion, like the pips of an orange) to take a more or less triangular 

 form. Thus then, he said in conclusion, in these cases, starting with 

 the form of the fruit, we see that it governs that of the seed, and that 

 the seed again determines that of the cotyledons. But, though the 

 cotyledons often follow the form of the seed, this is not invariably the 

 case. Other circumstances, as I have attempted to show, must also 

 be taken into consideration, and we can throw much light on the 

 varied forms which seedlings assume. 



I fear you may consider that I have occupied your time by a 

 multiplicity of details, and I wish I could hope to have made those 

 little plants half as interesting to you as they have made themselves 

 to me ; but, at any rate, I may plead that without minute, careful, and 

 loving study, we cannot hope in science to arrive at a safe and satis- 

 factory generalisation. 



The lecture was accompanied not only by numerous diagrams, but 

 by specimens, kindly lent by the authorities of Kew, and by some 

 practical illustrations. 



