38 M. DeCandolle on the relative Duration of the Power 



how this reference of the whole phenomenon to endosmose leaves 

 totally unexplained a series of such phenomena as the swelling up 

 of a particular region of cells in consequence of irritation in sen- 

 sitive plants. It may be also from the influence of the pheno- 

 menon in question, that in many plants the primordial utricle 

 separates from the cell-wall in the dead plant, and in this way 

 the cell-sap comes into direct contact with the cell-wall. How- 

 ever, it appears to me, as I have already remarked, that it is 

 rash at present to talk either about this or other possibilities, 

 since facts, on which a solid theory can be built, time has yet to 

 furnish us with. 



IX. — On the relative Duration of the Power to germinate, in Seeds 

 belonging to different Families. By M. Alph. DeCandolle *. 



(First experiment.) 



The relative permanence of the faculty of germination in dif- 

 ferent species of seeds has never been examined with the precision 

 that the present condition of science demands. The " practice" 

 of gardens has taught in a vague and superficial manner, that 

 certain seeds soon lose their power of germination, others but 

 slowly ; that the collecting of seeds, the manner in which they 

 are preserved, transported, and lastly, sown, influence greatly the 

 result of the sowings. It is well known that by a suitable degree 

 of humidity and heat, may be obtained the germination of seeds 

 which otherwise would remain inert or be spoilt. Facts of this 

 kind have resulted from the observation of every horticulturist, 

 and it would be useless to seek to contest them, because the con- 

 ditions of the sowings vary and are scarcely ever comparative. On 

 the other hand, physiologists have directed attention in their 

 works to the germination of some very old seeds f, but these are 

 isolated cases, perhaps exceptional, and which cannot be compared 

 with each other, since the seeds have been submitted to different 

 conditions. 



It appeared to me to be of some interest to ascertain the 

 faculty of germination, after a given lapse of time, in seeds, be- 

 longing to different families, but collected simultaneously in the 

 same garden, transported and preserved in the same manner, 

 finally, sown in equal number in similar conditions of soil, hu- 

 midity and temperature. Well-observed physiological facts have 



* From the Ann. des Sc. Nat., Dec. 1846. Translated by Arthur Hen- 

 frey, F.L.S. &c. 



f DeC. Physiol. Veget. p. 618 et seq. Desmoulins, Documents relatifs 

 a la faculty germinative conservee par quelques graines antiques. Pamphlet 

 in 8vo. Ed. 2. July 1846. 



