EMBRYOGBNIC METHOD 47 



on the special evolution of each of these great 

 types of organization. But on the other hand we 

 must examine with care on what palaeontological 

 bases the phylogenic deductions of the learned 

 zoologist of Jena rest. 



The group of Protozoa should comprise the most 

 simple as well as the most ancient types of the 

 animal kingdom. Haeckel supposes the existence 

 at the Laurentian epoch of types related to the 

 phases Moneron, Morula, Planula, and Gastrula ; 

 but these are simply visions of the mind. We shall 

 see in the chapter of this book devoted to the be- 

 ginnings of life on the globe that the only fact of 

 geological observation on which the hypothesis of 

 Haeckel rests that is to say, the famous Eozoon 

 canadense of the Laurentian gneiss of Canada, con- 

 sidered by Dawson and Carpenter as a giant Fora- 

 minifer must be reduced to the condition of a 

 simple miner alogical structure. 



The phylogeny of the Sponges and of the Acaleplis 

 or Medusae is founded, in Haeckel's book, on no 

 documents of a geological order. It is otherwise 

 with the Polyps or corals. The Tetracomls, or Corals 

 with four radiating walls, represent, according to 

 the author, the ancestral trunk whence started, 

 like two diverging branches, the two legions of the 

 Hexacorals and the Octocorals, characterized by six 

 and by eight radiating walls. Palseontologically, 

 the Tetracorals did, in fact, precede the other two 

 groups, and are particularly abundant in primeval 

 soils. 



The branch or phylum of the Worms naturally 

 offers us no palaeontological support by reason of 



