POSSIBILITIES AND PEOBABILITIES. 299 



observer to judge of the facts slionld be examined ; tbe 

 actual boundiug line between sensuous perception and 

 mental inference should be critically investigated ; and 

 confirmatory, yet independent, testimony should be sought. 

 Yet, when we have done all this, we should ever remember 

 that truth is stranger than fiction ; that our power to 

 judge of fixed laws is itself very imperfect ; and that 

 indubitable phenomena are ever and anon brought to 

 light, which compel us to revise our code. It is only a 

 few years since the existence of metamorphosis in the 

 Crustacea, when first announced, was scouted as absurd 

 by naturalists of high reputation ; and the wide pre- 

 valence of what is called Parthenogenesis in the Insecta 

 is even now lauo^hino- to scorn what had seemed one of 

 the most immutable laws of physiology.* 



I propose, then, to examine a few questions in natural 

 history, the very mooting of which is enough with many 

 to convict the inquirer of wrong-headedness and credulity. 

 High authorities — deservedly high, and entitled to speak 

 ex cathedra — have pronounced verdicts on them ; and 

 numbers of inferior name (as usual, going far beyond 

 their teachers,) are ready to treat with ridicule those 

 who venture to think that, in spite of the avrb^ ecpa, any 



* " Experience," says Sir J. W. Herschell, " once recognised as the 

 fountain of all our knowledge of nature, it follows that, in the study of 

 nature and its laws, we ought at once to make up our minds to dismiss 

 a*5 idle prejudices, or at least suspend as prematiu"e, any pre-conceived 

 notion of what might, or what ought to be, the order of nature in any 

 proposed case, and content ourselves with observing, as a plain matter 

 of fact, what is." — Prelim. Discourse, p. 79. 



