ActionScript: The Definitive Guide

Colophon

Our look is the result of reader comments, our own experimentation, and feedback from distribution channels. Distinctive covers complement our distinctive approach to technical topics, breathing personality and life into potentially dry subjects.

The animal on the cover of ActionScript: The Definitive Guide is a siren, a particular type of salamander with a tail; they diverged from other amphibian species (including frogs) early in amphibian evolution. All salamanders have smooth skin that is kept moist by secretions from numerous glands. when their environment becomes too dry, too hot, or too cold, the cold-blooded salamanders burrow into mud and their body functions slow down. Sirens develop cocoons to shelter themselves until conditions improve.

Sirens are considered very primitive salamanders, as they are aquatic (live permanently in water), lack hind legs, have reduced front legs, gills and other larval features into maturity, and their offspring are fertilized externally in the water. They are active at night, coming out and swimming much like eels do, using their dorsal fin in side-to-side motion to propel them forward. As they do so, they feed by gulping at insects and larvae. They expel plant matter through their gills.

Like all amphibians, sirens are an important part of a balanced ecosystem. They are small predators who in turn are preyed upon by fish and birds. Their glandular skin and fragile systems put sirens in the unfortunate position of being early pollution ...