Synthesis Summoner Question

[Srtz]

can a synthesis summoner use a Quadruped Eidolon?

The rules state that i need to have arms for somatic components to cast spells. Does that mean that that is a requirement to cast spells, or a requirement of the Eidolon from the start? for example i could still fuse with a quadruped eidolon that doesnt have arms, and just not be a able to cast spells until i use 2 evo's to get arms.

[LazarX]

Yes, you too can be Baron Karza. You do have to spend the evolution points to give yourself arms and hands if you want to be able to cast spells involving somatic components.

[Artanthos]

There is no requirement to take the arms evolution, but you will not be able to cast while fused, or heal your eidolon, until you do so.