Iagnemma’s characters are mostly scientists, authors of flawless proofs and theorems — but hopelessly confounded by love. In the title story of his inventive collection, an academic draws a Venn diagram of his love for his commitment-phobic girlfriend. In ”The Phrenologist’s Dream,” the 19th-century title character is tripped up by his lust for a bald woman after failing to read deceit in the bumps on her head. In ”Kingdom, Order, Species,” a young forester unsuccessfully tries to connect with lovers after sex by reading out loud from Woody Plants of North America. Fortunately, Iagnemma, a robotics researcher at MIT, is more adept at weaving marvelous, comic accounts of romance than his characters are at finding it.