About the narrating style:
The story is narrated with simple present tense. What is the function of simple present tense narration?
The ending coincides with the fact that the innocent in history (or "the simple" in Umberto Eco's phrase) is misled to favour those revolutionists who kill his family in blood. Ironically, the justice disguised under the name of revolution overweighs everthing, and some victims do not even feel uncomfortable about it.
Still, Cousin, as a revolutist, remains one part of the simple and the innocent. The ideology has taken roots in his mind that the sexual desire is despiteful and should be repressed, banned and spit at.
The book's title indicates the novel as the a quest story. The spiders' nests are identified with the suitcase in Pulp Fiction, by which the readers are aware their existence, where they locate, but are kept in suspicion of where they lead to or what they contain.
About the Preface:
The influence of history towards literature is sometimes indirected, slowly and contradictory. Many historical events happened without inspiring any great novels. (14)
"This is the first novel I wrote." The Preface, instead of talking about Calvino's first novel, in fact, talks more about the writing and the consequences of writing his first novel. and to elaborate it, writers' first books in general.
The first work indicates the birth of ONE from the nothingness ZERO, suggesting a drastic irrevocable change. By reading or even hearing about his first novel, the author's impression to the public is thus established, and the impression remains being associated with the author's name forever. That is in fact what Calvino felt remorse about. Yet, it might be true, but not that steadfast. Take Calvino himself for example, his following works, other than reinforce his first impression to the readers, redefine and remould his name as an author and an intellect.