Hi, I want to ask some questions about genetic programming.

Firstly, (1)Can each Individual classes separately hold trees in different number? 
So, first Individual holds 3 trees, second Individual holds 6 trees, ..., thirtieth 
Individual holds 10 trees and etc. Is this possible?

if this is possible, in default crossover class, for example (2)will the crossover 
be between first Individual's first tree and thirtieth Individual's first tree? or 
(3)can the crossover be first Individual's third tree and thirtieth Individual's sixth 
tree?

if the default crossover class can't do like this, can i manually write my own 
Crossover class that do crossover like i said in (3) questions?

Thanks.