You have seen that Cycads share many traits with Ferns. However, they have a Gymnospermous type of sexual reproduction . Gymnosperm means Naked Seed .
Seeds are mature Ovules .
The Integument has Vascular Tissues which are continuous with the Stele of the Sporophyte. Consequently, the Ovule can derive nutrition from the sporophyte during all stages of its development. If you reflect on Selaginella , you may recall that the Megaspores lie inside the Megasporangium which does not have a vascular connection with the Sporphyte. Megaspores are released before they are mature and complete their development in nature. Imagine that the Megasporophyll gradually enveloped the Megasporangium so that it was enclosed except for an opening at its tip.