55 



CHAPTEE VI 



THE CLASSIFICATION OF THE FOEAMINIFERA 



EvEEY classification is more or less artificial and 

 imperfect, and this nuist especially be the case with 

 a variable order of animals like the Foraminifera. 

 It is inconceivable that any type of animal life 

 underwent a series of changes in any direct line for 

 very long, without interference from dissimilar influ- 

 ences, the stronger prevailing ; and thus a devious 

 path would be tracked out, defying all our attempts 

 to place certain groups in definite order or sequence 

 with regard to others. Instead of a gradualty 

 branching phylogenetic tree we should, to be accu- 

 rate, have to make an arrangement taking the form 

 of a net, in which the species were represented by 

 the knots which unite the threads, the latter standing 

 for the series of intermediate forms connecting the 

 species. A difficulty would arise in determining 

 where the knots were to be placed — that is to say, 

 what were the types to be retained as such — and the 

 extent of the connecting threads. 



The division into genera and species is the 

 outcome of a selection of what the systematist is 

 pleased to regard as tj^pes, whilst the intermediate 

 conditions are either considered as varietal or, what 

 is more often the case, ignored altogether. It is 



