LANDMARKS OF BOTANICAL HISTORY -GREENE 309 



or striate, or fluted; and he is particular about mentioning every 

 such characteristic. Of still deeper interest are his dissections of 

 all manner of fruits, fleshy and capsular, and of seeds; but on 

 account of the taxonomic signiricancy of their results, these have 

 been reiated under another heading. 



The intimations of what seemed like a sense of feeling in some 

 mimosaceous foliage had been one of the wonders of plant phenom- 

 ena as observed by ancient Egyptians and Greeks. Cordus had 

 seen no mimosa, or sensitive acacia, but in two plants frequent in 

 German gardens he observed the foliage remarkably sensitive to 

 varying meteorological conditions. In his very full and minute 

 description of the licorice plant the first remark about the foliage, 

 after having stated its character as a compound leaf, is that its 

 leaflets exude some substance by which they adhere to one's fingers 

 when handled; then he proceeds to describe the several different 

 degrees of enfoldment or of expansion which the leaflets exhibit 

 according to the altitude of the sun on clear days, and how they 

 keep themselves folded together all day long if the sky be cloudy 

 or the weather wet or cold; concluding with the observation that 

 all this is true of the leaflets only, and that the leaf-stalk itself does 

 not alter its position at any time of the day, and that in all kinds of 

 weather its attitude is the same. 1 This last remark is called for 

 by what he had said in an earlier chapter about nyctotropic move- 

 ment in the common foenugreek. 2 In this he says the nightly 

 folding together of the leaflets is accompaniedby a deflection of the 

 whole leaf, petiole and all. 



In every description of a twining species of herb Cordus men- 

 tions the direction of the circumnutation, whether as following the 

 course of the sun or as taking the contrary direction. Of these 

 phenomena he is the first of all writers to make record, I think. 

 He was the first to describe the plant called sundew, 3 and its phy- 

 siology interested him. Its description occupies the first chapter 

 of the Historia, and as a new genus he would like to call it Rorella* 

 He seems to have perfectly established it, that what seems like 

 dew on the leaves of the plant is really an exudation ; for he says 

 that in the very driest weather the plant is still sprinkled all over 



' Hist. Pi., p. 1642. 



2 Ibid., p. 100. 



3 Ibid., p. 86. 



* Tragus had known Drosera rotundifolia, and has it figured as a species of 

 Polytrichum, P. minus (Stirp. Comm., p. 528). He said its habitat was "dewy 

 rocks, " and had no idea that the " dew " on its leaves was an exudation. 



