structures vs. instances

[abegel@media.mit.edu]

Which one takes up less memory per instance, a class instance or a structure
with the same information? 

I've defined a struct called pnt (gives the same functionality as the lisp
type point, but allows floats for the h and v) and I've been allocating
a bunch of them. In the course of allocating a few thousand of these,
my free memory ((ccl::%freebytes)) has dropped from 7 megs to 161K. 
Are structures garbage-collected? Almost all of these structures should have 
been garbage collected along time ago. 

Andrew Begel
MIT Media Lab
Epistemology and Learning
abegel@media.mit.edu