54 AN INTRODUCTION TO ZOOLOGY. 



had reason to fear the daylight of truth and the fresh 

 air of free opinion, or whose vanity led them to sup- 

 pose that in defending their own ignorant prejudices 

 they became thereby the champions of sacred and 

 holy things. The arbitrary bounds of species, fixed 

 as they had been often by the limited knowledge, and 

 sometimes by the unlimited pedantry, of the science 

 of a previous age, were consecrated as a sort of " Luck 

 of Edenhall," with the destruction of which all the 

 hopes of the human race would somehow vanish, and 

 leave the world a howling wilderness. The " Dar- 

 winian theory," and the negation of it, became the 

 shibboleths of opposing creeds : somewhat to the dis- 

 tress of the author of the theory ; for his mind, like 

 that of nearly all truly great men, . was constructive 

 rather than destructive in its energies, and he was 

 not iconoclastic. Few great men are ; for why should 

 those who can plant a truth that is new waste their 

 time in hedging and ditching by the wayside of 

 philosophy, hacking away rotten branches from the 

 old? 



Embryology as a key to the facts of Evolu- 

 tion. While a great impulse was given to the study 

 of natural history by these new ideas, numbers of 

 discoveries were being made which tended to confirm 

 them. Some of these were discoveries in the popular 

 sense of the word — discoveries of types of plant or 

 animal which had not been found before ; but other 

 and more valuable discoveries were made when the 

 insight of the investigator was directed to the study 



