Which kind of Mac do you have? As far as I remember its on the same cd and its for a Power PC MAC OS 10.3 or higher. Read the instructions to be sure.
I checked the offical site it appears that its a hybrid disk (meaning both are on the same disk)
Mac OS X v.10.3.9+
700 MHz G4 processor (Intel Core Duo or 1GHz G4 or faster recommended)
512 MB system RAM (768 MB or more recommended)
OpenGL enabled graphics card or chipset recommended (recent NVIDIA GeForce and ATI Radeon preferred)
24-bit color display, 1024 x 768 resolution
1 GB free hard disk space (4 GB recommended)
Internet connection required for Content Paradise
DVD-ROM drive
These are the spec for a Mac
http://my.smithmicro.com/win/poser/index.html use this to contact the manufacters maybe they can help you more with the install process or help you get a version you can install.