: This is true, but I think this remark was made in reference to the Balrogs only.

I think the remark applied to all Maia who took a real (flesh) form, as opposed to those who only took a visible form.

: : I think there was also ranking order among the Maiar. I don't know if this is actually stated in any of the text. Members of the higher order, Sauron and Istari for example, would take longer to become totally bound to their body. While others of the lesser orders,balrogs & dragons, would become totally bound sooner.

: There were certainly greater and lesser Maiar, however I don't think I would rank the Balrogs among the lesser ones. It is stated somewhere that even the dragons feared the Balrogs, so they must have been quite formidable. However, the tying of the spirit to the physical form was not necessarily a function of time or intrinsic power - Melkor himself had become bound to his 'body' by the time he faced Fingolfin in combat, and he was accounted the most powerful of the Valar (and hence, the most powerful being in Middle-earth). It was Melkor's squandering of his native power upon his 'creations' which caused him to become 'earthbound' as it were.

We don't know what the ranking order was among the Maiar. Balrogs may have indeed had more powers (strength) and been of a higher order, and therefore been feared by dragons. My point was that they were lesser in rank and power than Sauron and others of the highest order.I may indeed be possible that once a Mair of the balrogs rank took a flesh form they were unable to shed it.

Glaurung (sp?), if he actually was a Maia, seems to locked into his flesh form from the begining, or at least was at the time of his death. I don't remember his body falling into dust or disappearing immediately after he was slain. It is possible that the decendents of Glaurung were purely flesh creatures.

My understanding is that Melkor became trapped in his flesh body after aiding in the destruction of the trees and the stealing of the jewels. This occured when he returned to Middle Earth proper immediately following those events. I don't think is so said, but implication is that it was done by Eru as punishment.

We are, after all, talking of a Valar of the highest order. I doubt Melkor's spiritual form would have been destroyed if his physical body were destroyed.