1 88 NATURAL SCIENCE. March, 



placentas are of a deep blackish green, a partially-torn fruit is even 

 more conspicuous than an entire one, owing to the contrast between 

 the two colours. A species of Melothria, which I found in Perak, is a 

 small creeping gourd which frequents sandy spots. The fruit is dull- 

 coloured and adapted for dispersal by mice, which tear the gourd to 

 pieces and carry them away with the seeds. Hodgsonia heteroclita, 

 Hook, fil., frequents dense thickets on river banks. It bears very 

 large woody gourds, covered with a grey pubescence. These gourds 

 drop from the plant, when ripe, and float in the river. The pubescence 

 prevents them from injury by wet, so much so that a gourd may be 

 plunged in the water and taken out again dry. The seeds, too, are 

 large and woody ; they float in water and are protected from injury as 

 the pulp of the fruit is exceedingly oily. This is an example of 

 modification for dissemination by water. Zanonia macrocarpa is a 

 native of the densest hill-jungles of the Malay Peninsula and else- 

 where. Here are few birds or mammals to disperse the seeds by 

 swallowing or carrying them away, and no river to drift them. The 

 fruit is therefore adapted for dispersal by wind. It is a huge obconic 

 capsule, of a dull green colour ; when ripe, it splits across the top into 

 lobes, which recurve, and as, from its weight, it hangs with the 

 broadest part downwards, the thin winged seeds drift away through 

 the forest till they find a suitable spot to grow in. Finally, Ecballium, 

 a native of dry deserts where animals and birds are few, and where 

 there are no trees to climb up so that we might expect the seeds to 

 be adapted for dispersal by wind, possesses a remarkable mechanism 

 by which the seed is shot explosively to a sufficient distance from 

 the parent plant. These examples, however, do not exhaust the 

 minor modifications of the fruit in this remarkable order. 



The methods by which seeds are dispersed may be briefly 

 classed as : — 



(a) Dissemination by animals, either by their swallowing the 

 fruit, or seeds, or by bearing the seed to a distance in order to devour 

 it, or part of it ; or by accident in the case of adhesive seeds and 

 fruits. 



(b) By wind. 



(c) By water ; rain-drops, streams, or sea. 



(d) By mechanical means, such as an explosive mechanism, by 

 g, or by the mere inversion of the capsule. 



It may be well to point out first that Epiphytes are invariably 

 disseminated either by birds or by wind, and Saprophytes by merely 

 shaking the seeds out of their capsule, or by dissolution of the whole 

 fruit, when the seeds are carried away by rain-drops, or (more rarely) 

 by wind ; but in no case are they provided with plumes or other 

 appurtenances for wind-dispersal. Big trees and lofty climbers in 

 jungles and woods are disseminated by animals or wind, unless 

 habitually growing in or near the sea or rivers, when they are often 

 adapted for water-transport. With very few exceptions it is her- 



