(iii)  The tide-wave of incarnating
EGOS has rolled past them to harvest
experience in more developed and less
senile [declining] stocks; and their
extinction is hence a Karmic necessity."
*



9.)  .. the Americans have become in
only three centuries a "primary race,"
pro tem., before becoming a race apart,
and strongly separated from all other
now existing races.


(
i)  They are, in short, the germs of
the Sixth sub-race, and in some few
hundred years more
[HPB mentioned
this ~130 years ago],
will become
most decidedly the pioneers of that
race
which must succeed to the
present European or fifth sub-race
,
in all its new characteristics.

[ So before the Sixth Root Race, there
will only remain those Egos (Spiritual
Souls) regardless of skin color and
race, who
already passed through 7
seven sub-races, 7 branch races, etc
..
having become well-rounded and
pure
through selfless striving,
detached from earthly temptations,
and so forth..

So HPB was referring to mankind
(whether Oriental, Occidental, or other)
who achieved Buddhic or Christ
Principle
, aka Soul Union.  

Only this attainment matters! ]


(i)  Redskins, Eskimos, Papuans,
Australians [Aborigines], Polynesians,
etc., etc. -- all are dying out.


(
ii)  Those who realize that every
Root-Race runs through a gamut of
seven sub-races with seven branchlets,
etc., will understand the "why."
* Blavatsky, The Secret Doctrine Vol. II