326 THE COMING OF AGE OF 



meister has brought to light the extraordinary and alto- 

 gether unexpected modifications of the reproductive ap- 

 paratus in the Lycopodiacem, the Rhizocarpece, and the 

 GymnospermecB, bj which the ferns and the mosses are 

 gradually connected with the Phanerogamic division of 

 the vegetable world. 



So, again, it is only since 1859 that we have acquired 

 that wealth of knowledge of the lowest forms of life 

 which demonstrates the futility of any attempt to sep- 

 arate the lowest plants from the lowest animals, and 

 shows that the two kingdoms of living nature have a 

 common borderland which belongs to both or to neither. 



Thus it will be observed that the whole tendency 

 of biological investigation, since 1859, has been in the 

 direction of removing the difficulties which the apparent 

 breaks in the series created at that time ; and the recog- 

 nition of gradation is the first step towards the accept- 

 ance of evolution. 



As another great factor in bringing about the change 

 of opinion which has taken place among naturalists, I 

 count the astonishing progress which has been made in 

 the study of embryology. Twenty years ago, not only 

 were we devoid of any accurate knowledge of the mode 

 of development of many groups of animals and plants, 

 but the methods of investigation were rude and imper- 

 fect. At the present time, there is no important group 

 of organic beings the development of which has not been 

 carefully studied ; and the modern methods of harden- 

 ing and section-making enable the embryologist to de- 



