The doctrine of descent and Darwinism . FORMS ALLIED TO AMMONITES. 217 in the convolutions was to the spinous Ammonites anadvantage which would be established by selection. Ifother palaeontologists consider the fluctuations of formaccompanying the relaxation of the closed spiral asevincing the decline of the group, no contradictionseems to be implied, for what was originally used as anadvantage by natural selection, proved injurious in itsconsequences. As we have seen, the earliest states are obliterated to. such a degree by curtailment of development that theindication of the nature of the pr
The doctrine of descent and Darwinism . FORMS ALLIED TO AMMONITES. 217 in the convolutions was to the spinous Ammonites anadvantage which would be established by selection. Ifother palaeontologists consider the fluctuations of formaccompanying the relaxation of the closed spiral asevincing the decline of the group, no contradictionseems to be implied, for what was originally used as anadvantage by natural selection, proved injurious in itsconsequences. As we have seen, the earliest states are obliterated to. such a degree by curtailment of development that theindication of the nature of the progenitors continuallydiminishes. But our theory necessarily leads to theconviction that the families within which we have asyet been able to compare Ontogenesis with Philogenesis, 2l8 THE DOCTRINE OF DESCENT. constantly approximate in their origin, and vindicate theexpectation that at least here and there, in the indi-vidual development of single representatives of thevarious families, witnesses of their common derivationshould come to light. This likewise occurs, and tosuch a degree that in the earliest larval stages alink is established between the lowest and the highestanimals. If a number of groups of the lowest livingbeings, in which the various vital functions of nutrition,irritability, motion, and reproduction are supplied byamorphous protoplasm,—if these be separated, as byHaeckel, into a neutral kingdom, owing to the absenceof sexual reproduction, we must likewise agree withhim in attribut
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Keywords: ., bookauthorschmidtd, bookcentury1800, bookdecade1880, bookyear1882
