146 ON THE METHOD OF ZADIG. [LECT. 



why that sort of head and that sort of tail go together ; 

 what physiological connection there is between the 

 two. So, in the case of the Montmartre fossil, Cuvier, 

 finding a thorough opossum's head, concluded that the 

 pelvis also would be like an opossum's. But, most 

 assuredly, the most advanced physiologist of the 

 present day could throw no light on the question why 

 these are associated, nor could pretend to affirm that 

 the existence of the one is necessarily connected with 

 that of the other. In fact, had it so happened that 

 the pelvis of the fossil had been originally exposed, 

 while the head lay hidden, the presence of the "mar- 

 supial bones," however like they might have been to 

 an opossum's, would by no means have warranted the 

 prediction that the skull would turn out to be that of 

 the opossum. It might just as well have been like 

 that of some other Marsupial ; or even like that of 

 the totally different group of Monotremes, of which 

 the only living representatives are the Echidna and 

 the Ornithorhynchus. 



For all practical purposes, however, the empirical 

 laws of co-ordination of structures, which are embodied 

 in the generalisations of morphology, may be con- 

 fidently trusted, if employed with due caution, to lead 

 to a just interpretation of fossil remains ; or, in other 

 words, we may look for the verification of the retro- 

 spective prophecies which are based upon them. 



And if this be the case, the late advances which 

 have been made in palseontological discovery open 

 out a new field for such prophecies. For it has been 

 ascertained with respect to many groups of animals, 



