The Evolution of Fruits. 9 



inquiry as to the morphological nature of ovules, we may 

 perhaps safely assert that they are originally, normally, and 

 almost universally developed from the margin of carpellary 

 leaves. In djcas such an origin is obvious, for we have a 

 but slightly modified leaf, some lobes of which only are 

 transformed into ovules. In the Juniper the three scales at 

 the base of which the ovules are situated, becoming succulent, 

 simulate the berry amongst true fruits. In abnormal Prim- 

 roses the ovules are seen to spring from heel-like, auricular 

 appendages at the base of the carpellary leaves, and all the 

 evidence points to the origin of this order from a Caryophyl- 

 laceous ancestry, from which it differs only in having its 

 petals united. The originally marginal character of the 

 jolacentation of the Caryophijllacea is clearly seen, e.g., in the 

 carnations {Dianthus). The structure of those groups in 

 which the placentation is still simpler, such as the Pohj- 

 gonacea, in which there is a single ovule rising from the base 

 of the one-chambered ovary, may be best explained as 

 reduction from the same marginal type. 



The original fi'uit consisting then of a single carpellary 

 leaf or of several, the ovules in either case being marginal 

 structures, before tracing the general rules followed by 

 Nature in the variations of fruits, it is necessary to consider 

 the objects which fruits have to accomplish. The ultimate 

 object of the fruit is subsidiary to that of the seed — the 

 reproduction of the species. The immature seed requires 

 protection from decay-producing excess of moisture or from 

 the depredations of birds. The mature seed requires a non- 

 conducting covering, that it may not be stimulated into 

 premature germination by the deceptive warmth and moisture 

 of autumn. Many plants producing offsets and many seeds 

 necessarily falling near the parent plant, the species becomes 

 a social one, like the grasses of our temperate regions, in 

 which case the struggle for existence is more than usually 

 severe, the relations of each individual to its surroundings — 

 its hexicology — being similar to those of its neighbours, and 

 in no way complementary to them. Accordingly dispersion 

 is advantageous, especially to trees, beneath the shade of 



