1 88 THEORETICAL BIOLOGY 



organisms arise from out their own germ. Thereby a starting- 

 point is given in space for the genesis of all living things ; the 

 germ is the first building-stone, and, as soon as the later ones 

 are formed from it, they are obliged to take up a position in 

 relation to a spatial centre. If duplication follows, we get 

 the bilateral type. If the repetition is four- to sixfold, there 

 appear four-, five-, and six-rayed types. If the germ divides 

 up into several building-stones set one behind the other, we 

 get the segmented type. 



If we bear in mind that the germ of the children arises 

 from the germ-plasm of the parents, we shall understand that 

 the manifestations of like germs are similar. Hence the first 

 shapings of the germ which find expression in type-formation 

 yield the surest criterion of relationship. The morphologists 

 are justified, therefore, in ascribing fundamental importance 

 to the morphological type, when they attempt to mark off 

 from one another the circles of relationship in animals. 



It happens not infrequently that animals inhabiting the 

 same medium and living on the same prey, or hunted by the 

 same enemies, show, in correspondence with their approxi- 

 mately similar function-circles, a similar kind of construction 

 in their effectors and receptors. But such animals are not 

 related to one another, if the morphological laws of their 

 structure are different. They are analogous to one another 

 but not homologous. 



Inevitably we assume homologies between animals now 

 living and their ancestors, and up to this point it is justifiable 

 to employ the morphological laws of structure for the de- 

 termination of lineage. But we must altogether abjure 

 the Darwinistic misuse of these laws. 



Morphology is a science that concerns itself with the 

 centrifugal mode of structure of the cell-mosaic of which aU 

 organisms are composed. Where the support of embryology 

 is lacking — in palaeontology, for instance — morphology is con- 



