TABLE XXII. 



Systematic Sukvey of the Peeiods in the Teibal Histoey op the 



Human Eace. 



(Compare Table VIII., to), i. p. 402.) 



FIRST MAIN PERIOD IN TEIBAL HISTORY. 



The Flastid Ancestors of Han. 

 The form of the ancestors of man is equal to the simple individnal of the 

 first order, a single plastid. 



First Stage : Moneron Series (Fig. 163, p. 46). 

 The ancestors of man are single, living, simple cytods. 



Second Stage : Amoeba Series (Fig. 167 p. 53). 

 The ancestors of man are single, living, simple cells. 



SECOND MAIN PERIOD IN TRIBAL HISTOEY. 

 The many-celled Primitive Animal Ancestors of Man. 

 The ancestors of man consist of a closely -united society of many homo- 

 geneous cells ; hence their form-value is that of individuals of the second 

 order, of Idorgana. 



Third Stage : Synamoeba Series (Fig. 170, p. 55). 



The ancestors of man are many -celled primitive animals of the simplest 

 kind : solid masses of simple, homogeneous cells. 



Fourth Stage : Plausea Series (Figs. 172, 173, p. 60). 

 The ancestors of man are many-celled primitive animals of a character 

 like that of the Magosphaera and certain planula-larvae, of equal rank vrith 

 the ontogenetic Blastula or Blastosphm-a ; hollow spheres, the wall of which 

 consists of a single stratum of ciliated cells. 



