I think the author was inspired
to create the fictional Ralestone
family by the historic William
Ralston,confederate, who emigrated
to Brazil after the American Civil war....

Well, the author is hard on oriental
cultures, but that is a flaw of the times, specially on pulp fiction.
He is NOT as hard on the chinese as
R. Sabatini is on the Spanish.
Besides, considering how dumb the heroes, the police, and the british in general are portrayed, one might
say Sax Rohmer is hard on the british, too...
Also, Sax Rohmer has much more imagination and style than Sabatini.

Nice and thrilling.
I am firmly persuaded it was the inspiration for the Star Trek episode "What Are Little Girls Made Of?"

A classical farwest tale translated into a space adventure. A nice enough tale, though.

In fact the discussion on the
qualification of individuals as
human or not is quite presently
relevant. In fact, it is the crux of the discussion on the ethical
argument against abortion.
That makes it a quite relevant little
moral tale...

It is an old horror plot
projected in a spacefaring
scenario.

A very interesting tale of
problem-solving. Four earthmen against an extra-terrestrial empire and their indestructible envoy.