PAINTERS AND POETS 



common ancestor, have had extraordinary influence in over- 

 throwing the unintelligent pedantry so prevalent until 1875. 



Yet there were many, not always botanists, of much older 

 date, who made great discoveries in the science. Leonardo 

 da Vinci, the great painter, seems to have had quite a 

 definite idea of the growth of trees, for he found out that 

 the annual rings on a tree-stem are thin on the northern and 

 thick on the southern side of the trunk. Dante ^ seems to 

 have also understood the effect of sunlight in ripening the 

 vine and producing the growth of plants {Purgatorio^ 

 XXV. 77). Goethe seems to have been almost the first to 

 understand how leaves can be changed in appearance when 

 they are intended to act in a different way. Petals, stamens, 

 as well as some tendrils and spines, are all modified leaves. 

 There is also a passage in Virgil, or perhaps more distinctly 

 in Cato, which is held to show that the ancients knew that 

 the group of plants, Leguminosae, in some way improved 

 the soil. I have also tried to show that Shelley had a more 

 or less distinct idea of the " warning " or conspicuous colours 

 (reds, purples, spotted, and speckled) which are characteristic 

 of many poisonous plants (see p. 238). 



But if we begin with the unlettered savage, one can trace 

 the very slow and gradual growth of the science of plant-life 

 persisting all through the Dark Ages, the Middle Ages, and 

 recent times, until about fifty or sixty years ago, when a 

 sudden great development began, which gives us, we hope, 

 the promise of still more wonderful discoveries. 



^ *• Guarda il calor del sol che si fa vino 

 Giunto all' umor che dalla vite cola." 

 He is speaking of wine — that "lovable blood," as he describes it. 



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