A photo of what seeds look like in pantyhose

While most iris seeds have two  germination blocks (need for vernalization and  anti-germination chemical), aril seeds sem to have a third barrier,  the hard shell. this needs a third process involving what is called "Scarification". this needs to be dealt with by damaging external  seed shell. This can be done by nicking seed, scaring by sandpaper etc, or a chemical treatment such as an acid bath.   Best to get advice on this third process from  someone  who has delt with these seeds.

Chuck Chapman