Inquiry into the Structure vf Seeds. 229 



gardeners preserve melon and cucumber seeds, perhaps for 

 years, that the plants they produce may be less luxuriant, in 

 consequence of being starved at their first germination ; for 

 any injury to the cotyledons, even after they begin to rise 

 above ground, is found to cramp the subsequent growth of 

 the plant. The oU of the cotyledons has been usually sup- 

 posed a protection to their internal parts, T presume against 

 wet; but this purpose it by no means does or can answer, 

 for aU seeds readily absorb moisture whenever they meet 

 with it, and, if likewise exposed to the action of oxygen, 

 they vegetate, in whatever situation they may otherwise 

 happen to be. I suspect moreover that the oily and muci- 

 laginous fluids of seeds in general, before they perform their 

 office in germination, all previously become milky, and often 

 saccharine, from the actions of water and oxygen. It might 

 be worth while to inquire, whether exposure of such seeds 

 as are most prone to turn rancid, to a quantity off oxygen # 

 would tend to preserve them. It is, I believe, found that 

 the admission of some atmospheric air is necessary to the 

 preservation of many seeds. The primary cause of decay 

 therefore in seeds spoiled by keeping may originate, not, as 

 I have supposed, in the extinction of their vital principle, 

 but in the corruption of their albuminous oils ; and this ra 

 strengthened by the experiments of the French chemists, 

 whose applications may much more readily be supposed to 

 correct and restore the albuminous juices, than to bring the 

 dead to life. 



This idea of the albuminous matter, whether oily, muci- 

 laginous, or farinaceous, being, when not a distinct and 

 separate body, always lodged in the cotyledons, throws ad- 

 ditional light on the nature of the last-mentioned parts, and 

 m a very beautiful manner confirms their analogy with 

 leaves. The discoveries of Mr. Knight have proved that the 

 nutritious fluid or sap of plants is carried into the leaves, in 

 order to be there acted upon by air, light, heat, and mois- 

 ture. After these agents have produced their effects, the 

 fluids are sent back, through the returning vessels, into the 

 branch or stem, to furnish matter of increase to the whole 

 vegetable body. The chemical experiments, of Dr. Priestley 



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