I am in the process of monitoring every species that I can get my hands on so that I will have a normal growth chart for as many as possible ies that I can get my hands on so that I will have a normal growth chart for as many as possible. Twenty eggs is the minimum number in my opinion that is required to produce one of these growth charts. At the end of each season all the data is collated with results from previous years so that some of these growth charts are averages obtained from an everincreasing number of eggs.