This poem is a set of three limericks composed by Asimov collaborating with his wife. The basic conceit is that primeval cells got bored with reproducing asexually, so “Together they clung; grew complex./Fully half went concave, half convex;…And announced the invention of sex.”
I'm not an enormous fan of Asimov’s limericks at best (see Lecherous Limericks, Asimov’s Sherlockian Limericks, and Isaac Asimov’s Limericks for Children), and although these three are relatively clean, they are also only moderately clever. The last one is the only one to bring even the slightest smile to my lips. On the whole, this is a rather disappointing addition to a generally disappointing book, Laughing Space.