AMENTAOE.E 



365 



though the actual place of attachment remains the 

 same. The Oak, in fact, seems to have appreciated 

 the difficulties of the situation, and to have in great 

 measure neutralised them. Is it fanciful to imagine 

 that some ages hence the Oak may be practically 

 orthotropous ? 



But why should these species be anatropous if it is 

 an advantage to be orthotropous ? On this question 

 some light is thrown by the fact that while one seed 

 only comes to maturity, the ovary contains originally 



Fig. 261.— Friut and seed of Oak. 

 u, placental axis ; ch, chalaza ; 

 m, niicropyle ; o, abortive ovule. 



Fig. 252. — Fruit and seed of Nut. Nat. 

 size. cA, cliala^a ; m, mycropyle ; o, 

 abortive ovule ; pi, placental axis ; v, 

 raphe. 



several cells, each with one or two ovules, though none 

 of the others comes to anything. They can, however, 

 easily be seen, either at the apex of the seed, as in the 

 Nut (Fig. 252) and Beech (Fagus), or, as in the Oak 

 (Fig. 251), near the base. Their presence appears to 

 indicate that these species are descended from ancestors 

 the fruit of which was composed of several cells, each 

 with more than one seed — a, state of things, therefore, 

 very unlike the present, and in which the anatropous con- 

 dition would be an advantage. If this view be correct, 

 the structure of the fruit in the Nut, Beech, and others 

 becomes peculiarly interesting, because it represents a 

 case in which the present arrangements are not those in 

 all respects most convenient to the plant, and renders it 

 probable that the same explanation may apply to other 

 cases of difficulty. 



