l66 GEOLOGICAL BIOLOGY. 



method of organic development, is called histogcny, or liisto- 

 gcncsis — the origination or development of tissues ; and the 

 terms cryptogoiy and cryptogciicsis may be used to distinguish 

 from it the first method of organic development, which ends 

 in the reproduction of cellular units, and is confined to simple 

 enlargement of the cell, as in the Protozoa. 



Histogenesis, Cryptogenesis, and Phylogenesis. — In histogenesis 

 the organic unit is enlarged by the division of the initial cell 

 into many separate cells forming a compound organism known 

 as the metazoal individual. In cryptogencsis the organic unit 

 is a simple cell. As histogenesis begins with cryptogencsis, 

 and is an enlargement of the scope of organic growth, so we 

 may conceive oi phylogenesis SiS an enlargement of histogenesis, 

 in which the unit is the organic species, and the progress is in 

 terms of specific forms, new species arising by evolution of 

 the old and modification and expansion of the ancestral types 

 in their descendants. The growth is growth of the race, and 

 the specialization is in functions of the individuals, first seen 

 in the production of sex ; this specialization is further de- 

 veloped in the co-ordination and co-operation of the members 

 of a family, and is still more highly elaborated in the com- 

 munity or the race. 



Analogy between the Cell and Organism and the Molecules, 

 Elements, and Minerals of Inorganic Matter. — -The results of these 

 several modes of growth of the organism are analogous to the 

 categories used in chemical nomenclature. There are physical 

 units which are called molecules, which may be compared to 

 cells, the organic units. The chemical element is a molecule, 

 or mass of molecules, exhibiting uniform properties, or chem- 

 ical reactions. A mineral is a combination, or it may be a 

 simple element, exhibiting definite and uniform chemical 

 composition, and physical characters of weight, hardness, 

 crystalline structure, etc. As the molecule is resolvable into 

 imagined atomic constituents, so the organic cell is resolvable 

 into its protoplasm, and according to the theories of some into 

 innumerable pangenes or ids, each having its personal char- 

 acteristics. 



The Individuality of the Organism. — On the other hand, as 

 any particular mineral exists only temporarily and under 



