270 The Scottish Naturalist. 



have the stony or leathery carpels enclosed in a fleshy flower- 

 stalk so closely that it seems to form a part of the carpels. 

 This is eaten by animals, and the seeds, alone or enclosed in 

 the carpels, are distributed, when voided, to some distance 

 from the tree on which they grew. Thus among our native 

 Rosacea we meet with nine different adaptations for distribution 

 of the seeds; — five specially suited for passing through the 

 bodies of animals, two for conveyance attached to fur or 

 feathers, and two for distribution by wind. Similar facts may 

 be elicited bv an examination of other natural orders, but need 

 not be dwelt on at present. 



In conclusion, it may not be amiss to point out that the 

 various adaptations occur only under such conditions as are 

 directly useful and beneficial to the plant in promoting the 

 wide dispersion of its seeds, either alone, or still enclosed in 

 the ovary. Modifications in the seeds themselves occur only 

 in such fruits as open to allow the escape of the seeds. It is 

 only in these that we find loose seed-coats, or wings, or hair- 

 tufts ; very rarely are hooks or spines found on seeds, as they 

 would apparently be in the way in the ovary. Again, modifica- 

 tions in the ovary, suiting it for conveyance by wind or attached 

 to bodies of animals, are found only in ovaries that contain one 

 or two seeds, and that do not open, but themselves break off 

 from the parent plant, and are dispersed as if they were seeds. 

 In like manner the parts eaten by animals, whether an arillus, 

 or the ovary itself, or some outer part of flower or flower-stalk, 

 always inclose the seed or seeds in such a way as to ensure the 

 great likelihood of their being swallowed without injury. Modi- 

 fications of the envelopes, of the flower-stalk, or of the bract, 

 suited for dispersion by wind, or by attachment to the bodies of 

 animals, are found only in those cases in which the part modified 

 breaks off from the plant, and continues attached to the ovary. 



From an examination of the structures of plants in view of 

 the dispersion of seeds, we are warranted in believing that we 

 may succeed in understanding something of the way in which 

 specialisation of parts to ends is brought about to meet the con- 

 ditions of healthy vitality, while we find here as everywhere 

 economy of force, and adaptations of means to ends ungrudg- 

 ingly, but with no trace of waste of power. 



