1881, 



Fruits (lud Seeds. 



007 



described by Hildebraiid. Tlio interior of the fruit is oceupied by loose 

 cellular structure. The central column, or 2)lacenta, to wliicli the 

 seeds are attached, lies loosely in this tissue. Througli the solution 

 of its earlier attachments, when the fruit is ripe, the column adlieres 

 only at the apical end, under tlie withered remains of the flower, and 

 at the swollen side. Wlien the fruit bursts the 2)lacenta unrolls, and 

 thus hurls the seeds to some distance, being even itself sometimes also 

 torn away from its attachment. 



Other cases of projected seeds arc afforded by ITiira one of the 

 EujjJtorhice, Cvllomuij Oxalis, some species allied to Acanthus, and by 

 ArceutJiohium, a plant allied to the mistletoe, and parasitic on Junipers, 

 which ejects its seeds to a distance of several feet, throwing them thus 

 from one tree to another. 



Even those sjiccies which do not eject their seeds often have them 

 so placed with reference to the capsule that they only leave it if 

 swung or jerked by a high wind. In the case of trees, even seeds 

 with no sj^ecial adaptation for dispersion must in this manner be often 



carried to no little distance ; and to a certain, 



Fig. 11, 



though less extent, this must hold good even 

 with herbaceous plants. It throws light on the, 

 at first sight, curious fact that in so many plants 

 with small, heavy seeds, the caj^sules open not at 

 the bottom, as one might perhaps have been dis- 

 posed to exj^cct, but at the top. A good illus- 

 tration is alforded by the well-known case of the 

 Common Poppy (Fig. 11), in which the upjier 

 part of the capsule i^iesents a series of little doors 

 (Fig. 11 a), through which, when the plant is 

 swung by the wind, the seeds come out one by 

 one. The little doors are protected from rain 

 by overhanging eaves, and are even said to shut 

 of themselves in wet weather. The genus 

 Camimmda is also interesting from this jioint of 

 view, because some species have the capsules 

 pendent, some upright, and those whicli arc 

 upright open at the top, while those which are 

 pendent do so at the base. 



In other cases the dispersion is mainly the 

 work of the seed itself. In some of the lower 

 plants, as, for instance, in many seaweeds, and in 

 some allied fresh- water plants, such as Vducherin, 

 the spores * are covered by vibratile cilia, and 

 actually swim about in the water, like infusoria, 

 till they have found a suitable spot on whicli to grow. Nay, so much 

 do the spores of some seaweeds resemble animals, that they are 



Sccd-hcnd of Poppy 

 (/'(ij^aft'r). 



♦ I need hardly observe that, botauically, these are not true seeds, but nithcr 

 motile buds. 



