320 THE DOCTRINE OF DESCENT. 
natural extinction of the individual; a fourth portion might 
possess the properties requisite for self-preservation as well as for. 
the preservation of the genus, yet lacked that peculiar tendency 
to vary (Philosophie des Unbewussten, p. 591), or at least that ten- 
dency to vary in the particular direction which was alone capable 
of leading to development into higher forms; and finally a fifth 
portion possessed this property in addition to the others. It is the 
progeny of the fourth and fifth classes of our division which still 
populates the ocean and the earth.* From which species of 
Monera proceeded the advanced development of the Infusoria ; 
whether from one still living or from an extinct species we do not 
know as yet ; but this much we may accept as certain, that the 
majority of the Protists that we still know, belong to that fourth 
class which is incapable of development. The persistence of the 
ephemeral creations of our second and third classes would natu- 
rally be secured only so long as circumstances continued favour- 
able to their renewed primordial generation, but from the teleo- 
logical standpoint the first class must be described as that of the 
completely abortive attempts at creation.” 
These, and similar more or less interesting fancies to which we 
attribute no great importance, are all derived from Haeckel’s 
hypothesis of Autogony (“Generelle Morphologie der Organis- 
men,” 179 seq.), which he set up after his beautiful discoveries on 
the simplest organisms now existing—the Monera and the Protists. 
From this work we select the following passage :—“ Doubtless we 
must imagine the act of autogony, the first spontaneous origin of 
the simplest organisms, to be quite similar to the act of crystal- 
lization. In a fluid, holding in solution the chemical elements 
composing the organism, in consequence of certain movements of 
the various elements among themselves, certain points of attraction 
are formed, at which the atoms of the organogenetic elements 
(carbon, oxygen, hydrogen, nitrogen) enter into such close contact 
with one another that they unite in the formation of a complex 
ternary or quaternary molecule. This primary group of atoms— 
perhaps a molecule of albumen—now acts like the analogous crystal- 
* It is a simpler and more probable explanation that these low organisms 
continue to exist because there is room for them. They remain in spite of 
differentiation and in consequence of differentiation, ‘ 
