to germinate, in Seeds belonging to different Families. 39 



always value in themselves. I foresee moreover, in the present 

 case, certain applications to geographical botany. Thus the du- 

 ration of the faculty of germination, be it absolute or relative, 

 may have an influence on the frequency of the individuals of each 

 species, on their appearance in new localities the nature of which 

 has changed, and, when the seeds have been deposited a long 

 time, on the effect of transportation from one country to another, 

 and in general on the geographical extension of species. 



The idea of ascertaining facts of this kind occurred to me in 

 1832, when I made the observations which are contained in the 

 1 Physiologie Botanique ' of my father*, on the relative rapidity 

 with which germination takes place in the different families of 

 plants. I then preserved packets of seeds in order to sow them 

 after a certain number of years, and as in the summer of 1846, 

 the students who were attending the higher course of botany 

 showed themselves disposed to aid me in some researches or ex- 

 periments, 1 recollected my store of old seeds and arranged to 

 sow them at once. 



The principal collection which I chose for the experiment had 

 been sent in 1832 from the Botanical Garden at Florence. The 

 seeds had therefore been collected in 1831, and when I sowed 

 them on the 14th of May 1846, they were all nearly fifteen years 

 old. During this long space of time they had been preserved in 

 a dark cabinet, out of the influence of humidity or extreme vari- 

 ations of temperature. There were several hundreds of them, but 

 I was satisfied with taking, at random, 368 species belonging to 

 a large number of different genera and families. That the com- 

 parison might be exact, it was necessary to sow an equal number 

 of the seeds of each species. I fixed upon the number 20. 

 It was a long and tedious operation to pick and count them, 

 throwing away such as appeared spoilt. In most instances it 

 was necessary to use a lens. Seeing how many thousands of 

 seeds were included in the sowing of certain species, I could not 

 help thinking that the small seeds germinate less frequently than 

 the large, and I suspected that the contrary opinion held by gar- 

 deners resulted from the enormous inequality of the number in 

 the sowings of small and large seeds. The result of our experi- 

 ment should confirm one or other of these two opinions. The 

 seeds were sown in pots, in peat mould, in order to avoid weeds, 

 of which in fact there were but a very small number. The seeds 

 were watered from time to time. The mean temperature of the 

 month of June, the period when several species sprung up, was 

 19° Centig. (about 66° Fahr.) j that of July 18°- 5 Cent., according 

 to observations at nine in the morning and nine at night, pub- 



* Physiol. Bot. p. 639 et seq. 



