HAECKEL^S ANTHROPOCfENIE, 23^7 



of membranous and calcareous coverings as well as nutritive matter, 

 in tlie shape of food-yolk and albumen. Tlie food-yolk (red) is 

 easily distinguished from the germinal yolk (white), and most of the 

 latter is found at one point on the surface (cicatricula), with the 

 nucleus imbedded in it. It is only this portion of the white yolk 

 ^which after fertilization and fission forms the germinal membrane. 



By the application of Haeckel's "biogenetic fundamental laWj^," we 

 can thus infer a unicellular ancestral form^ most likely amoeboid from 

 the occurrence of amoeboid eggs in the lower anirdals, and the wide 

 distribution of such cells in the higher animals (blood, &c.) The mode 

 in which the unicellular organism is transformed into a colony of cells 

 might be arrived at d priori by reflection on the way in which a 

 colony would be formed by a male and female savage thrown on an 

 uninhabited island. At first merely nutrition and reproduction are 

 attended to ; but by the dispersion of children families are constituted, 

 reciprocal relations established, and the principle of the division of 

 labour steps in, its result the development of castes. So it is with the 

 cell : at first the individuals are of equal physiological value ; but as 

 the principle of the division of labour begins to operate, different cells 

 are set apart to perform difierent functions; so that- reproductive 

 cells, muscular cells, nerve cells, protective cells, &c., replace the 

 formerly uniform mass. 



The functions that are especially engaged in individual as well as 

 in phylogenetic development are the following: Nutrition, adaptation, 

 growth, reproduction, heredity, differentiation, retrogression, concres- 

 cence. Of these heredity, adaptation and growth are most efficient 

 in determining form. Heredity, conservative as well as progressive, 

 is intimately connected with reproduction f adaptation, which initiates 

 all variations, with nutrition ; in fact, all of these functions are- 

 dependent the one on the other. Growth is surplus nutrition, and 

 reproduction surplus growth. Differentiation, or the division of 

 labour, occu.rs in phylogenesis as it occurs in a state, in ontogenesis as 

 the result of heredity : the gradual disappearance or degradation of 

 some of the cells may be for the advantage of the colony, and this 

 leads us to the formation of rudimentary organs. Concrescence also 

 is connected with reproduction, or rather occurs in both forms of 

 sexual reproduction (true sexual reproduction and conjugation). 

 Those tissues which perform the highest functions are formed of cells 



