The
ler braid is made up of 4
parents, who
mate in all possible
combinations over a period of 10
years, producing one
child from each mating.
The first pair of parents in a braid have the first child, called the nerh or elder outsibling. Then at the female's next fertile period, 5 years later, each of these mate with another adult who is just at the start of the period of fertility. Each parent chooses a mate for the other in this phase. The children that result from this arrangement are called toorh, or insiblings. Finally, 5 years later, the parents brought in during the previous round mate and have the fourth child of the braid, known as thes or younger insibling.
Pheromones released at the time of the second mating usually assure that the insiblings are of opposite gender, and these insiblings (who, keep in mind, have neither the same father nor mother - no incest here) become the first parents of the next generation of the braid. The outsiblings move into other braids at the time of their fertility.
If a braid has two same-sex insiblings, then, unless they work out an exchange with another braid in a similar but opposite situation at the same age, the braid ends. Besides these leftover insiblings, there are also zerh, or extra children, the result of third fertilities, which occur in a small fraction of ler, and twins, which occur even more rarely, and hifzer, roughly equivalent to bastards, children born outside of the braid relationship. These collected extras occasionally form new braids, and those who do so have a choice no other ler have: the choice of their own mate.