“If he insists on feeding the infant jaguar himself, in defiance of its mother’s wishes, there may be another by-election in the north,” said one of his colleagues, with a hopeful inflection in his voice. “By-elections are not very desirable at present, but we must not be selfish.”
What is the difference between "another by-election" and "by-election"?
It's a highly context-specific allusion to the fact that there had already been at least one by-election in the North of England recently (the story was written around 1914). This isn't explicitly stated earlier in the story, but it's strongly implied by the preceding paragraph which makes many references to political unrest.
Most likely the speaker represents or endorses the current ruling class, which is why he says By-elections are not very desirable at present (since he and/or his allies are currently in power, they'd rather keep it that way and not risk losing control "bit-by-bit" through by-elections).
And certainly the readers of the time would know all about Britain 1911-1914: The great unrest.
Compare...
1: Do you want a slap?
2: Do you want another slap? (by implication, in addition to the slap/s you've already had)
another by-election
is talking about the possibility of a specific by-election, whereas
by-election
is talking about by-elections (any) in general.
