292 



SCIENCE. 



[N. S. Vol. I. No. 11. 



the hypothesis is too apt to be capable of 

 endless coutractions and modifications to 

 meet individual cases. I sometimes think 

 that we are substituting for the philosophy 

 of observation a philosoj)hy of definitions. 

 I have, therefore, attempted to show : 



1. That the plant is not a simple aiitono- 

 my in the sense in which the animal is. 



2. That its parts are virtually independent 

 in respect to (a) propagation (equally either 

 when detached or still persisting upon the 

 parent plant), (b) struggle for existence 

 amongst themselves, (c) variation, (d) 

 transmission of their characters, either by 

 means of seeds or buds. 



3. That there is no essential difference 

 between bud-varieties and seed-varieties, 

 apart from the mere fact of their unlike 

 derivation ; and the causes of variation in 

 the one case are the same as those in the 

 other. 



4. That all these parts are at fii-st sexless, 

 but finally may or may not develop sex. 



5. That much of the evolution of the 

 vegetable kingdom is accomplished by 

 whoUj^ sexless means. 



There is, then, a fundamental unlikeness 

 in the ultimate evolution of animals and 

 plants. A plant, as we ordinarily know it, 

 is a colony of potential individuals, each one 

 of which, save the very first, is derived from 

 an asexual parent, yet each one may, and 

 usually does, develop sex. Each individual 

 is capable also of receiving a distinct or pe- 

 culiar influence of the environment and 

 struggle for existence, and is capable, there- 

 fore, of independent permanent modifica- 

 tion. It is not possible, therefore, that there 

 is any localization or continuity of a germ- 

 plasm in the sense in which these concep- 

 tions are applied to animals ; nor is it pos- 

 sible for the plant as a whole to make a 

 simple functional adaptation to environ- 

 ment. If there is a continuity of germ- 

 plasm in plants this element must of neces- 

 sity be intimately associated with every par- 



ticle of the plant body, even to its very pe- 

 riphery, and it must directly receive external 

 impressions ; and this concept of AVeismann 

 — the continuitj'' of the germ-plasm — ^be- 

 comes one of the readiest means of explain- 

 ing the transmission of acquired characters. 

 All these conclusions prove the unwsdom 

 of endeavoring to account for the evolution 

 of all the forms of life upon any single 

 hj'pothesis ; and thej' illustrate with great 

 emphasis the complexitj^ of even the funda- 

 mental forces in the progression of organic 

 nature. L. H. Bailey. 



CoENELL University. 



CUEBENT NOTES ON PHYSIOGBAPHY {III.). 

 woodward's smithsois'iaiv geographical 



TABLES. 



' The average geographer,' to whose needs 

 Professor Woodward has attempted to suit 

 the recent volume of Geographical Tables 

 issued by the Smithsonian Institution, 

 should certainljr feel liighly complimented 

 by this ti-ibute to his quality. The volume 

 contains, among manj' other matters, tables 

 of coordinates for the projection of poly- 

 conic maps, lengths of a degree on parallels 

 and meridians at different latitudes, areas 

 of latitude-and-longitude, quadi'ilaterals of 

 diiierent dimensions and at different lati- 

 tudes, adopted dimensions of the earth's 

 spheroid, value of gi-avity at the earth's sur- 

 face, and salient facts of phj'sical geodesj'. 

 The latter heading includes the ai-ea of the 

 earth, of oceans and continents, and the 

 average heights of continents and depths of 

 oceans, taken from Helmert's Geodiisie. For 

 areas the continents are given 51,886,000, 

 and the oceans 145,051,000 square miles. 

 The mean depth of the oceans is placed at 

 3,440 meters. The mean heights of the con- 

 tinents are given as follows : The earlier re- 

 sults of Humboldt's, still often quoted, and 

 the later ones of Penck (Morphologic der 

 Erdoberfliiche, 1894) being added for com- 

 parison. 



