Hello Cambron,
Thanks for all the information.

Yes, I am sure of Donald C Christie's dates. They are on his tombstone in the Breadalbane Cemetery, Utica, Ontario. It gives this birth date and says he was born in Perthshire. He died in 1904 and is buried with his wife Jane and his 2 eldest children, Peter and Christina.
Donald C. Christie's father was Donald (1796-1844), son of Donald Christie and Jean McIntyre. Sorry, I wasn't clear in my original post - since Donald Sr. died in 1844, his widow is on the censuses. Her name was Mary Munro. I am quite sure that she is NOT Donald C. Christie's mother, but I would like to be able to prove it conclusively with a christening record.
2 related branches of the Christies of Perthshire came to Canada and settled in the same place. They use the same names for their children, so it can get quite complicated sorting them out. The name Donald is particulary popular. Some of the census records you mentioned are for my branch, some are for the other!
As for the christening records you mentioned, John Christie and Janet McAlpin are from the other branch of the family, but John Christie and Jean McLaren are from mine. Their son Donald also married a woman named Jane - but he is a cousin to Donald C. Christie.
Was it the custom in Scotland at that time to christen the children within a couple of weeks of their birth? If people waited longer than that, maybe he was christened in Canada? I had never considered that before. Though I would be a bit surprised if they would attempt an ocean voyage without christening a child.
RK