CHARLES DARWIN. 453 



author made in the summer of 18G0, when he "was surprised by 

 finding how large a number of insects were caught by the leaves of 

 the common Sun-dew {Drosera rotundifulia), on a heath in Sussex." 

 Almost everybody had noticed this; and one German botanist (Roth), 

 just a luindred years ago, had observed and described the movement 

 of tlie leaf in consequence of tiie capture. But nothing came of it, 

 or of what had been as long known of our Dioncea, beyond a vague 

 wonderment, until Mr. Darwin took up the subject for experimental 

 investigation. The precursor of his volume on " The Movements and 

 Habits of Climbing Plants," published in 1875, as well as of the 

 recent and larger volume on " The Power of Movement in Plants," 

 1880, was an essay published in the Journal of the Linnean Society 

 in 1865 ; and this was instigated by an accidental but capital obser- 

 vation made by a correspondent, in whose hands it was sterile ; but 

 it became wonderfully fertile when touched by Darwin's genius.* 

 His latest volume, on " The Formation of Vegetable Mould through 

 the Action of Worms," is a development, after long years, of a paper 

 which he read before the Geological Society of London in 1837. 



These subsidiary volumes are less widely known than those of the 

 other class ; but they are of no less interest, and they are very char- 

 acteristic of the author's genius and methods, — characteristic also of 

 his laboriousness. For the amount of prolonged observation, watch- 

 ful care, and tedious experiment they have demanded is as remarkable 

 as the skill in devising simple and effectual modes of investigation is 

 admirable. That he should have had the courage to undertake and the 

 patience to carry on new inquiries of this kind after he had reached 

 his threescore and ten years of age, and after he had attained an un- 

 paralleled breadth of influence and wealth of fame, speaks much for 



* Mr. Darwin's quickness in divining tlie meaning of seemingly unimportant 

 tilings, is illustrated in his study oi Dioncea. Noting that the trap upon irritation 

 closes at first imperfectly, leaving some room within and a series of small inter- 

 stices between tiie crossed spines, but after a time, if there is prey within, shuts 

 down close, he at once inferred that this was a provision for allowing small in- 

 sects to escape, and for retaining only those large enough to make the long pro- 

 cess of digestion remunerative. To test the surmise, he asked a correspondent 

 to visit the habitat of Dionma at the proper season, and to ascertain by the ex- 

 amination of a large number of the traps in action whether any below a certain 

 considerable size were to be found in them. The result confirmed the inference. 

 A comparatively trivial but characteristic illustration of Darwin's confidence in 

 the principle of utility, and a good example of the truth of the dictum, which 

 was by some thought odd when first made, namely, tliat Darwin had restored 

 teleology to natural history, from which the study of morphology had dissev- 

 ered it. 



