How to get classes to associate with each other without using 'use'?

[ItecKid]

Ok, so I have to write two (OO) Perl modules. One the them, in one of it's subroutines, needs to call the constructor of the other module. According to my professor, this should be doable without the classes having working knowledge of each other.

For example, if I have:

package ItecKid::A::First;

#constructor goes here...

#the create subroutine is supposed to create an object of
#type ItecKid::A::Second.
#How to do this step?

sub create {
#acquire arguments with shift;

#this is how I tried to do it:
my $self = ItecKid::A::Second->new ();  #assuming the constructor is called new.
}

But then it complains to me about not being able to use the 'Second' module. How to go about doing this?