How Plants Secure Change of Location 401 



calamity. Some seed pods, by action of hygroscopic mechanisms, 

 open only when the weather is favorable for the particular mode 

 of dissemination of their seeds, whether this requires wetness or 

 dryness. And there are yet other disseminational adaptations, 

 some real, some accidental, some imaginary, described in the 

 works of Kerner and of others already referred to in the foregoing 

 pages.* 



When we view as a whole the results attained through these 

 modes of dissemination, and note how wide is the spread some 

 plants have secured through the world, it becomes plain that in 

 the long run the sum total of the accomplishments of the non- 

 locomotive plants in this regard, is no whit inferior to that of the 

 highly-locomotive animals, if not indeed markedly superior 

 thereto. This shows the efficiency of the dissemination methods, 



* Dissemination, dealing with prominent and highly developed adaptations, has 

 always been one of the favorite topics of ecological study; and it affords valuable 

 material alike for amateur investigation, for student themes, and for popular scientific 

 articles in the illustrated magazines. In the hope that the reader may ^vish to follow 

 this subject more deeply than my limits allow, I add here the titles of the principal 

 accessible works upon it. The foundation work is Hildebrand's Die Verbreitungsmiitel 

 der Pflanzen (Leipzig, 1873), an admirable, but all too brief a treatise, which, un- 

 fortunately, has never been translated. There is a wonderfully clear and well- 

 illustrated accoimt in Kerner's Natural History of Plants (translated by Oliver, 

 New York, Henry Holt & Co., 1895). One of the best synopses, illustrating the 

 striking cases, is Beals' excellent little book. Seed Dispersal (Boston, Ginn & Co., 

 1898), while much briefer though good are Weed's Seed Travellers (Boston, Ginn & 

 Co., 1898) and a chapter in Lubbock's Flowers, Fruits, and Leaves (London, The 

 Macmillan Co., 1886). Of articles accessible in magazines the best are Folsom's 

 Adaptations of Seeds and Fruits, in Popular Science Monthly, 1893, 218, and es- 

 pecially Ridley's Dispersal of Seeds by Birds, in Natural Science, Vol. 8, 1896, 186, 

 one of the very best discussions of this subject anywhere in print. And of course, 

 there is a host of special papers of all degrees of technicality in the various scientific 

 magazines. Considering the attractiveness of the subject, it is very remarkable that 

 nobody has yet undertaken to prepare a modern cyclopedic work upon it, something 

 comparable with the books we possess for cross pollination; and I commend this 

 subject to any ambitious young naturalist among my readers, warning him that the 

 task is vast and will take him nearly a lifetime, but assuring him that it offers an 

 opportunity for just such a distinctive and useful piece of work as most men find the 

 greatest satisfaction in doing. There is not in science any kind of a book that is so 

 lasting in value as this, excepting only the one which presents material wholly new. 



