Dr. GREGORY. A tumbling is a second--it actually is a third component of motion that a missile may go through in its trajectory. First, there is a linear motion from muzzle to target on point of impact. In order to keep a missile on its path, there is imparted to it a rotary motion so that it is spinning. Now, both of these are commensurate with the constant trajectory. A third component, which is tumbling, and is literally the end over end motion, which may be imparted to a missile should it strike something in flight that deflects but does not stop it--in this circumstance the wound of entry created by such a missile usually is quite large and the destruction it creates is increased, as a matter of fact, by such tumbling, and I would have therefore expected to see perhaps some organic material carried into a large wound of entry in Governor Connally's back. These are only theoretical observations, but these are some of the reasons why I would believe that the missile in the Governor behaved as though it had never struck anything except him. Mr. SPECTER. Did you observe the nature of the wound in the Governor's back? Dr. GREGORY. Only so far as I saw it as Dr. Shaw was preparing to operate on it, but I was unable to see the nature of the wound as he carried out his operation. I did, however, specifically question him about this matter of containing foreign material, clothing, etc. Mr. SPECTER. What did he say about that? Dr. GREGORY. Well, as I recall it, he said none was found, and I would not have expected any to be found as I explained to you, if this was the initial impact of that missile. Mr. SPECTER. Well, wouldn't you think it possible, bearing in mind that my last question only went as to whether the same bullet could have gone through President Kennedy and inflicted the wound on Governor Connolly's chest, would you think it possible that the same missile could have gone through President Kennedy in the way I described and have inflicted all three of the wounds, that is, the entry and exit on the chest, the entry and exit on the wrist, and the entry into the thigh which you described. Dr. GREGORY. I suspect it's possible, but I would say it would have to be a remarkably powerful missile to have done so. Mr. SPECTER. Dr. Gregory, have you been interviewed about this matter prior to today by any representative of the Federal Government? Dr. GREGORY. Yes; on two or three occasions I have talked to a properly identified member of the Secret Service, Mr. Warren, I believe it was. Mr. SPECTER. And what was the nature of the information which you gave to Mr. Warren on those occasions? Dr. GREGORY. Essentially the same thing as I have told you here, but in much less detail. Mr. SPECTER. And have you ever talked to anyone besides Mr. Warren and me about these matters, from the Federal Government?