Jansy Mello: It occurs to me that "clystère de Tchékhov" is not only a cruel reference to Chekhov's advice [ "Chekhov's gun is a dramatic principle which requires that every element in a narrative be necessary and irreplaceable, and that everything else be removed", wiki ], but it equally promotes a distancing effect in the author by having been expressed in French. After all, in opposition to Chekhov, Nabokov enjoyed the cluttering effect of  "red herrings" and crowds of incidental figures.

I remember that he, in his lecture on Charles Dickens, praised the inclusion of an unnecessary coachman, who flipped his coin in the air and disappeared from the story. It's when Nabokov observes that: "A great writer's world is indeed a magic democracy where even some very minor character, even the most incidental character like the person who tosses the twopence, has the right to live and breed."LL,124).

Yes! In ADA, too, there are various instances in which Nabokov introduces a character and warns the reader that this person was of no consequence to the plot and would not recur. I didn't find the examples I had in mind, but here is one that's close to what I mean but not really demonstrative: "The discomfitured machine was abandoned under a shrub to be fetched later by Bouteillan Junior, yet another household character." - but I'm certain that most of you remember such instances...

There is a direct jab at Chekhov, though: "In the first edition of his play, which never quite manages to heave the soft sigh of a masterpiece, Tchechoff (as he spelled his name when living that year at the execrable Pension Russe, 9, rue Gounod, Nice) crammed into the two pages of a ludicrous expository scene all the information he wished to get rid of, great lumps of recollections and calendar dates — an impossible burden to place on the fragile shoulders of three unhappy Estotiwomen. Later he redistributed that information through a considerably longer scene in which the arrival of the monashka Varvara provides all the speeches needed to satisfy the restless curiosity of the audience. This was a neat stroke of stagecraft, but unfortunately (as so often occurs in the case of characters brought in for disingenuous purposes) the nun stayed on, and not until the third, penultimate, act was the author able to bundle her off, back to her convent." [ contrast that summing up sith Ada's observation concerning an English novelist: "as Jane Austen might have phrased it, for the sake of rapid narrative information (you recall Brown, don’t you, Smith?)."]