reds and
even thousands of sub-castes. These sub-castes had little or nothing of
the original racial significance. But they were all just as exclusive as
the primal trio, and the outcome was a shattering of Indian society into
a chaos of rigid social atoms, between which co-operation or even
understanding was impossible. The results upon Indian history are
obvious. Says a British authority: "The effect of this permanent
maintenance of human types is that the population is heterogeneous to
the last degree. It is no question of rich and poor, of town and
country, of employer and employed: the differences lie far deeper. The
population of a district or a town is a collection of different
nationalities--almost different species--of mankind that will not eat or
drink or intermarry with one another, and that are governed in the more
important affairs of life by committees of their own. It is hardly too
much to say that by the caste system the inhabitants of India are
differentiated into over two thousand species, which, in the intimate
physical relations of life, have as little in common as the inmates of a
zoological garden."[193]

Obviously, a land socially atomized and politically split into many
principalities was destined to fall before the first strong invader.
This invader was Islam. The Mohammedans attacked India soon after their
conquest of Persia, but these early attacks were mere border raids
without lasting significance. The first real Mohammedan invasion was
that of Mahmud of Ghazni, an Afghan prince, in A.D. 1001. Following the
road taken by the Aryans ages before, Mahmud conquered north-western
India, the region known as the Punjab. Islam had thus obtained a firm
foothold in India, and subsequent Moslem leaders spread gradually
eastward until most of northern India was under Moslem rule. The
invaders had two notable advantages: they were fanatically united
against the despised "Idolaters," and they drew many converts from the
native population. The very antithesis of Brahminism, Islam, with its
doctrine that all Believers are brothers, could not fail to attract
multitudes of low-castes and out-castes, who by conversion might rise to
the status of the conquerors. This is the main reason why the
Mohammedans in India to-day number more than 70,000,000--over one-fifth
of the total population. These Indian Moslems are descended, not merely
from Afghan, Turkish, Arab, and Persian invaders, but even more from the
mil