True, it doesn't answer that question one way or another. But I mentioned it, even though it seems likely anomalous, because it might be consistent with "Kzin" being the singular form, if the "Kzin" in "Kzin planet" were a
noun adjunct, since the rule for such modifiers is usually to use the singular form. But then again, "Kzinti government," another phrase occurring in the episode, might also appear to be such a construction and thereby consistent with the proposition that "Kzinti" is the singular form. So, it's a wash, really, based on what's available in the episode.
Personally, I take it that "the Kzin planet" is merely an alternate phrasing of "the planet Kzin." It seems to me to refer to the
planet itself by name, even if it is oddly phrased in context. At the most, it possibly indicates that
Kzin can also be used as an adjective like
Kzinti (see below).
I do not think that "the Kzinti government" and "a Kzinti spacecraft" should be construed as indicating that the singular term for one individual is "a Kzinti" in strict onscreen canon, even wholly ignoring the clear counter-indications in the production materials. (Not only in this script, but also in
that of "The Time Trap" and its related storyboards, where the Kzinti member of the Elysian Council is referred to as a
Kzin in clear context of other species names given in the singular form:
"...twelve men and women are seated on a dais. Each is a member of a different race: Klingon, Tellarite, Kzin, Orion, Andorian, Vulcan, Human, Gorn and three other alien types we have never seen before. See attached sheet for reference. Their spokesman is XERIUS, a tall Romulan with piercing eyes.")
"The British government" would operate "a British spacecraft," and the people as a whole might be referred to as "the British," but that doesn't mean one of them is referred to as "a British" (full stop).
I think that as a noun
Kzinti is used collectively referring to the whole species together ("the Kzinti aren't supposed to have weapons"; "a new war between Man and Kzinti") and in the plural referring to multiple individuals ("it has the Kzinti frightened"). It is also used as an adjective attached to another noun, as in the cases above. Never once in any aired episode is it used to refer to a singular individual. So, to me that seems an entirely unsupported assumption to make based on strict onscreen canon. And the TAS production materials (not to even mention Niven's other works, or real-world examples) clearly show it is a particularly
bad assumption to make, because they demonstrate that in spite of the collective/plural/adjectival forms all being the same, the singular form is intended to be different.
For reference, these are all the uses of
Kzinti and
Kzin in the aired episode:
- SPOCK: ...a Slaver stasis box discovered by archaeologists on the planet Kzin.
- SPOCK: The Kzinti now possess our stasis box.
- SPOCK: A Kzinti spacecraft.
- SULU: Kzinti aren't supposed to have phasers, are they?
- UHURA: I've heard all Kzinti telepaths are unhappy neurotics.
- SPOCK: But the Kzinti are meat eaters.
- SPOCK: In the presence of the Kzinti, do not say anything...
- SPOCK: Are you forgetting Kzinti females are dumb animals? In an emergency the Kzinti may forget a human female is an intelligent creature.
- SPOCK: ...but we may be able to seize an opportunity to escape if the Kzinti believe you have none.
- CHUFT-CAPTAIN: Kzinti archaeologists found both boxes...
- SULU: The Kzinti fought four wars with humankind and lost all of them.
- SULU: Then you're really working for the Kzinti government!
- CHUFT-CAPTAIN: If we are captured, the Highest of Kzin will repudiate us.
- SPOCK: The Kzinti now possess a weapon potentially deadly to the entire galaxy.
- SULU: They can call for help from the Kzin planet if they think the weapon's worth it.
- SULU: As long as you stay free, the Kzinti can't or won't do anything. But they could use Lieutenant Uhura as a bribe.
- SPOCK: Kzinti ribs have some vertical bracing.
- SULU: If the Kzinti had that, the whole galaxy would be their dinner table.
- SULU: It has the Kzinti frightened.
- SPOCK: The Kzinti have legends of weapons haunted by their owners.
- SPOCK: If not the Kzinti, the Klingons or some other species would have tried to possess it.
- SPOCK: That ancient war could have sparked a new war between Man and Kzinti.
- UHURA: Didn't you say the Kzinti have legends of weapons haunted by their dead owners?