Full Idea
It seems to me that it is right to call a lion's offspring a 'lion' and a horse's offspring a 'horse' (I'm talking about natural offspring, not some monster). ...but by the same argument any offspring of a king should be called a 'king'.
Gist of Idea
The natural offspring of a lion is called a 'lion' (but what about the offspring of a king?)
Source
Plato (Cratylus [c.375 BCE], 393b)
Book Reference
Plato: 'Complete Works', ed/tr. Cooper,John M. [Hackett 1997], p.112
A Reaction
The standard modern difficulty is whether all descendants of dinosaurs are still called 'dinosaur', which they are not.