THE DARWINIAN THEORY 27 



which occurs in many crustaceans, and in aphides and certain worms, 

 was recognized at that time, and in the sixties Carl Ernst von Baer 

 added to the Kst precocious reproduction, or paedogenesis, which is 

 illustrated in certain insects which reproduce in the larval state. 



This may suffice to convey some idea of the great mass of new, 

 and in some cases startling facts previously unguessed at, which were 

 then brought to light in the department of animal biology alone. To 

 this must be added the vast increase in the number of known species 

 and varieties, their distribution on the earth, and all this, Tnutatis 

 mutandis, for plants also. Nor can we omit to mention the rapidly 

 growing number of fossil species of animals and plants. 



Thus there gradually accumulated a new mass of matei'ial ; 

 investigation became raOre and more specialized, and the danger 

 became imminent that workers in the various departments would 

 be unable to understand each other, so completely were they inde- 

 pendent of one another in their specialist researches. There was lack 

 of any unifying bond, for workers had lost sight of the general 

 problem in which all branches of the science meet, and through which 

 alone they can be united into a general science of biology. The time 

 had come for again combining and correlating the details, lest they 

 should grow into an unconnected chaos, through which it would be 

 impossible to find one's way, because no one could overlook it and 

 grasp it as a whole. In a word, it was high time to return to general 

 questions. 



Though I have called the period from 1830 to ]H6o that of 

 purely detailed research, I do not mean to ignore the fact that, 

 during that time, there were a few feeble attempts to return to 

 the great questions which had been raised at the beginning of the 

 century. But the point is, that all such attempts remained unnoticed. 

 Thus there appeared, in 1844, a book entitled Vestiges of the Natural 

 History of Creation, the anonymous author of which revealed himself 

 much later as Robert Chambers, an Edinburgh publisher. In this 

 book the evolution of species was ascribed to two powers, a power 

 rbf transformation and a power of adaptation. Two Frenchmen, 

 VNaudin and Lecoq, also published a work in which the theory of 

 evolution was set forth, and from 1852 to 1854 the well-known 

 German anthropologist Sehaafhausen was writing on similar lines. 

 But all ■ these calls sounded unheard, so deeply were naturalists 

 plunged in detailed investigations, and it required a much mightier 

 voice to command the ear of the scientific world. 



It is impossible to estimate the effect of Darwin's book on The 



