ABUNDANCE OF HYPOTHETICAL STAGES. 153 



once more to the subject of paleontology, into which 

 we need not again enter. To a certain extent, 

 naturalists have succeeded in finding among fossils 

 remains of animals which may well be these hypo- 

 thetical forms, but it must be confessed that their 

 success has not been very great. Aside from the 

 general imperfection of the geological record, several 

 distinct reasons can be given for this. Firstly, 

 most of these stages, concerning which embryology 

 teaches us, must have lived far back, in ages 

 which have left few fossils. But, secondly, we notice 

 that embryology can give us only the general char- 

 acteristics of these forms, and says not a word as to 

 their specific features. Now, every fossil must have 

 specific as well as general features, and the presence 

 of the former, which are often more prominent, may 

 obscure the latter. Thirdly, all of these stages 

 would resemble, more or less, one of the groups 

 which they connect. If our paleontologist should, 

 therefore, find an imperfect representative of such 

 a connecting link, he would usually class it with one 

 or the other group, without recognizing its imme- 

 diate character. It is not improbable that the fish- 

 scales found in the Silurian age belonged to one of 

 the very hypothetical stages of which embryology 

 teaches, but how are we to know whether it be so 

 or not? These scales come nearer to those of a fish 

 than to any thing else we know, and they are there- 

 fore said to belong to a fish. The absence of these 

 hypothetical stages is, therefore, not very surprising, 

 though it is certainly unfortunate. 



