Calvin had his nine month pediatrician appointment this morning and the consensus is that all is well. Better than well, actually. 
The pediatrician said that he is well ahead of the game on physical development, and his verbal development is right on track (no more worrying for his parents, then). He measured over 28 inches, putting him in the 50th percentile for height (a good place to be) and weighed in at a healthy 19 pounds, which puts him in the 35th percentile for weight (the doctor thought this was probably due to how extremely active he is all day every day!), 
and his head circumference fell in the 75th percentile. We got the go-ahead for lots of new foods, the first of which will be cheese - yay!
Then this afternoon we were blessed with such a beautiful spring day that Cortney and Calvin just couldn't stand to spend it indoors, so instead they took a long walk, followed by some driveway playtime. Calvin was really too young to truly enjoy outdoor playtime the last time that it was warm, 
so this was really like an introduction to him, and, as usual, he took it very seriously. It wasn't long before he made it very clear that he intended to eat as much of the outdoors as possible, but his mother made that goal very difficult (no, Calvin, we don't eat rocks). Eating or not, however, he was more than a little disappointed about having to go inside for a real lunch (until he saw the banana, that is).