88 LECTURES 



of man. Carrying these studies a little further along 

 and we lay down the true principles which constitute 

 the foundations of the science of sociology, which, in 

 truth, is nothing more than the science of social phe- 

 nomena as exhibited in human society; and its growth 

 clearly shows it to belong to the group of biological 

 sciences. 



As already intimated, we may, in the future, and that, 

 too, for many ages to come, look forward to an ever- 

 increasing knowledge of the science of distribution the 

 distribution of animals and plants both in space and in 

 time. Whatever may be the amount, however, of this 

 knowledge yet to be possessed, we can hardly look for 

 anything more than an amplification, by an accumula- 

 tion of an enormous array of additional facts, of the 

 scheme and of the laws of distribution as they are now 

 known to us. Progress in this science, in the future will 

 consist in a refinement in detail of what we already know 

 about the distribution of the world's existing florae and 

 faunas. Many new species of organisms will come to 

 light, but as they do we will sooner or later come to be 

 familiar with their exact geographical ranges. Among 

 the minuter forms of life this will, of course, 

 requires much research, extending over many 

 ages of time; and in the case of the vast majority of the 

 smaller types of marine life it will require a considerably 

 longer time before we will possess any exact knowledge 

 on the subject, more especially in the case of the deep- 

 sea forms. Indeed we may add here that there probably 

 yet remain unknown to us myraidsof interesting animals, 

 of all kinds, in the ocean's depths, but even these the 

 labors of our marine zoologists are slowly bringing to 

 light. As to the distribution of plants and animals in 

 time, pretty much the same kind of progress is indicated. 

 Our palseozoologists and our paleeobotanists in the 

 future, no doubt will have their explorations rewarded 

 by the discovery, ever and anon, of many specimens of 

 fossil plants and animals long since extinct. These dis- 

 coveries will in their turn react by shedding an ever-in- 

 creasing light upon the question of the distribution of 

 animal and plant life as we now find it in the world, and 

 thus solve many problems which are, as yet, quite ob- 

 scure. Notwithstanding this view of the case, we may 

 look at any time for interesting developments all along 

 the line; such as, for example, the discovery of vertebrate 

 life in the Cambriam, a most important discovery re- 



