44 M. DeCandolle on the relative Duration of the Power 



Tiliacecz. Urticacece. 



Corchovus olitorius. Datisca cannabina. 



Triumfetta triclada. Urtica pilulifera. 



UmbeWferte. Valerianece. 



. . , Centranthus ruber. 



Ligusticum apioides. 



Hasselquistia cordata. Verbenacea. 



Bupleurum semicompositum. Lantana involucrata. 



CEnanthe Phellandrium. Verbena urticaefolia. 



Bupleurum junceum. officinalis. 



Anthriscus vulgaris. Priva mexicana. 



Selinum lineare. Vitex Agnus-castus. 



Conium maculatum. Stachytarpheta angustifolia. 



Biforis flosculosa. aristata. 



Eryngium asperum. Lippia rubra. 



One is struck, at the first glance, at the very small number of 

 species which germinated. By counting, we find seventeen out 

 of 386. Moreover the germinative power was much weakened in 

 those which did come up. In fact, out of the seventeen species 

 which came up, Dolichos unguiculatus is the only one that yielded 

 more than half the seeds sown (fifteen out of twenty). The others 

 had, for the most part, one, two or three germinations in twenty 

 seeds. Lavatera cretica approached nearest to Dolichos, but 

 there were only six seeds which germinated out of twenty. 



The different natural families may be classed as follows ; com- 

 mencing with those where the largest proportion of species pre- 

 served the power of germinating, and ending with those where, 

 more than ten species having been sown, none came up. 



Malvaceae, of which came up 5 out of 10 species sown, or 0-50 



Leguminosae, 



Labiataa, 



Scrophulariaceae, 



Umbelliferae, 



Caryophyllaceae, 



Graminaceae, 



Cruciferas, 



Compositae, 



No conclusion can be drawn from the fact, that none came up 

 out of nine Amaranthaceae, nine Ranunculaceae, eight Chenopo- 

 diaceae, eight Verbenaceae, seven Solanaceae, six Papaveraceae, 

 six Rubiaceae, &c, nor from that, for example, the single Balsa- 

 minaceous plant sown came up, for the numbers are too small, 

 and the result perhaps depends on the selection of the seeds 

 sown representing these families. That which comes out in a 

 very evident manner is the superiority of the Malvaceae and Le- 

 guminosae as to the duration of the faculty of germination, and 

 the inferiority of the Compositae, Cruciferae and Graminaceae. 



In this comparison of the families, we are obliged to leave on 

 one side a large number of species. This is not the case when 



