“The Flibotsi live inflissits, w hich are built high around the trunks of great trees, roofed with thatch and caulked with fresh moss that takes root on the sides of the structure and soon covers the entire flissit, making it both weathertight and cushiony. When well sheathed by moss, the flissits completely disappear into the forest scene, small ones for one Flibot, larger ones for two or three or even more, so that nothing intrusive or untidy mars the beauty of the landscape. Though there were a hundred flissits within seeing distance of the glade where we feasted, I doubt that you noticed even one of them, for the Flibotsi have a horror of what I have heard you, Benita, refer to as ‘tackiness.’
“Very large flissits in giant trees provide apartments for the empresses and their consorts as well as for hatcheries, brooders, and nurseries for the young. The moss covering royal flissits is of a different sort, a paler green, and it grows down the trunk of the tree and then spreads radially, though very slowly, bits of it running off in all directions, like the spokes of a wheel. It has a strong, pungent, though not unpleasant odor.
“Vess and I, together with a consultant committee of proffi, scientists, physicians, and the like, set about determining why male eggs were not being laid. The cause was not environmental, the soil and water and air had no poisons in them. We found no inimical radiation, nothing in the food or drink. It wasn’t genetic. It wasn’t the weather or the climate or some new cultural habit that had recently begun. In fact, everything we postulated failed to prove out. “When everything else had been exhausted as a possibility, Vess and I decided to go on to our last resort: hanging about and chatting with people. No matter how pleasant, one must put this off, as otherwise one might be misled. Once there is no other recourse, however, one may relax and enjoy it.
“So we talked to the empresses, who are rather complacent and preoccupied with their sex lives. And to the unsexed ones, who are mostly delightful. And to the male partners, who are the only Flibotsi to demonstrate what you on Earth callangst. We asked all kinds of questions. We chatted with aged brooder and incubator managers, with ancient gardeners, one of whom actually gave us the first clue. “ ‘In my day/ it said, ‘when I was under-gardener to old Flargee at Empress Magh’s, there wasn’t another empress within flying distance. Now, well, now, there’s Empress Irin, Empress Flitch, Empress Moggys, Empress Tryff, Empress (so on and so on, as the gardener listed a dozen or more) all within a bit of a fly, and many close enough to walk to!’
“This rang a bell with me, and with Vess. Something we had heard or seen or read about. We sat up late that night, in a visitors’ flissit, thinking and chatting, hoping some idea would pop out of the moss walls. In fact, I said at one point, ‘Some idea should pop out of the moss walls, and Vess said, That’s it.’“
“Vess reminded me that there are certain trees and mosses and other plants that make a kind of herbicide in their roots or leaves, and this chemical keeps other trees or bushes or mosses from growing in their immediate vicinity. Sometimes it keeps all growth away, sometimes only certain growths. You have such trees on Earth, dear Benita. The black walnut tree, I believe is one. Such a compound would not be something one would look for when seeking pollutants or poisons.
“So, we sent for moss samples from the flissits of the Empresses in the neighborhood. We found that each moss was slightly different, each exuding a slightly different pheromone, each one lethal to the male sperm in any vlasiput except that of the local empress. We sent for samples of the moss in the wild and found it exuded no pheromones at all.
“This was interesting. We obtained samples of skin and flesh and fluids from the empresses and immediately hit, as you say, pay dirt. The empresses have highly individual attractant odors that are produced during their first mating flights and continue to exude during their lives, a kind of olfactory fingerprint. During the mating flights, the particular scent is fixated upon by the males. Thereafter, a mated male cannot be utilized by any other empress. It would do no good, as that empress would not have the proper pheromone.