190 MISCELLANEOUS OBJECTIONS, ETC. [CHAP. VIL 



different and abrupt manner. Such an admission, however, ought 

 not to be made without strong evidence being assigned. The 

 vague and in some respects false analogies, as they have been 

 shown to be by Mr. Chauncey Wright, which have been advanced 

 in favour of this view, such as the sudden crystallisation of 

 inorganic substances, or the falling of a facetted spheroid from 

 one facet to another, hardly deserve consideration. One class of 

 facts, however, namely, the sudden appearance of new and distinct 

 forms of life in our geological formations supports at first sight 

 the belief in abrupt development. But the value of this evidence 

 depends entirely on the perfection of the geological record, in 

 relation to periods remote in the history of the world. If the 

 record is as fragmentary as many geologists strenuously assert, 

 there is nothing strange in new forms appearing as if suddenly 

 developed. 



Unless we admit transformations as prodigious as those 

 advocated by Mr. Mivart, such as the sudden development of the 

 wings of birds or bats, or the sudden conversion of a Hipparion 

 into a horse, hardly any light is thrown by the belief in abrupt 

 modifications on the deficiency of connecting links in our geological 

 formations. But against the belief in such abrupt changes, 

 embryology enters a strong protest. It is notorious that the 

 wings of birds and bats, and the legs of horses or other quadrupeds, 

 are undistinguishable at an .early embryonic period, and that they 

 become differentiated by insensibly fine steps. Embryological 

 resemblances of all kinds can be accounted for, as we shall 

 hereafter see, by the progenitors of our existing species having 

 varied after early youth, and having transmitted their newly 

 acquired characters to their offspring, at a corresponding age. The 

 embryo is thus left almost unaffected, and serves as a record of 

 the past condition of the species. Hence it is that existing species 

 during the early stages of their development so often resemble 

 ancient and extinct forms belonging to the same class. On this 

 view of the meaning of embryological resemblances, and indeed 

 on any view, it is incredible that an animal should have undergone 

 such momentous and abrupt transformations, as those above 

 indicated ; and yet should not bear even a trace in its embryonic 

 condition of any sudden modification ; every detail in its structure 

 being developed by insensibly fine steps. 



He who believes that some ancient form was transformed 

 suddenly through an internal force or tendency into, for instance, 

 one furnished with wings, will be almost compelled to assume, 

 in opposition to all analogy, that many individuals varied 

 simultaneously. It cannot be denied that such abrupt and great 

 changes of structure are widely different from those which most 

 species apparently have undergone. He will further be compelled 



