A. DeCandolle on the Life and Writings of Vaucher. 247 



croscope, and which nevertheless are not yet solved, or have 

 not even been touched upon. 



1. To sow varieties of pears, apples, vines, &c, well known, 

 well verified and protected from increase by transfer of pollen, 

 in order to know which are the qualities that are preserved by 

 seed, during how many generations, and with what degree of 

 constancy they keep themselves distinct. It is clear that com- 

 plete descriptions of the plant must be made at each genera- 

 tion, and that drawings or models in wax of the fruit obtained 

 must be preserved. The young and persevering, or those who 

 leave after them children endowed with the spirit of observa- 

 tion, may study this important question, the consequences of 

 which in natural history, both theoretical and practical, are 

 incalculable. 



2. To make similar observations on cultivated annual or 

 biennial species, when there is no hope of seeing the fruit of 

 sown trees ripen. 



3. To verify the duration of the faculty of germination in 

 seeds, not only in the air, but also in fresh and in salt water. 

 Experiments made in sea-water would possess great interest, 

 by showing what plants may possibly have been transported 

 by marine currents to great distances, and what plants must 

 have originally sprung up in the isles wherein they now grow. 

 It would be necessary to extend these experiments to a great 

 number of species of different families. 



4. To describe plants in the following manner, which 

 would complete existing botanic works. On the examination 

 of each species to read the description of two or three of those 

 classical works which are in every amateur's library, and at 

 the same time M. Vaucher's book ; then to add all that is 

 wanting. It would be seen that in general the most common 

 species are not known in all respects ; that, for example, the 

 vernation of the leaves has been overlooked, or their dispo- 

 sition on the stem according to the modern methods, or their 

 inflorescence, or aestivation, or any other of those characters 

 on which attention has been fixed since the time of the publi- 

 cation of certain fundamental works. 



5. To note down every year not only the period of flower- 

 ing which has often been remarked, but also that of the folia- 

 tion, of the ripening of the fruits, of the fall of the leaves, and 

 even, when it is possible, of the ascending sap in spring and 

 in summer. Good and long-continued observations of this 

 kind would approximate to tables of temperature ; in short, 

 we should know the heat necessary for each function in each 

 species, and thence many applications to agriculture and to 

 geographical botany. 



