From the preface:
"Up to now, game masters relying strictly on the sholari guide in the boxed edition have had to restrict their players to one of three races, all human-type descendants from the original Earth colony. Although humans, muadra and boccord have offered a range of attributes and talents for players, there has always been a strong desire on the part of players to experience the thrill of playing another race entirely. Playing the Iscin Races not only adds crugar and woffen to the list of choices, but it also for the first time, offers some real insight into the 'lost children of Iscin,' the tologra (historically, culturally and playably!)
Note: Blount are not heavily covered in this book because we feel that only a very small minority of players would actually derive satisfaction from asuming the role of a dim-witted, swam-dwelling, mathin-carrying frog for any length of time.
The final version of this book will be released in Fall of 1989 and will include additional information on the bronth as well."