In Katharine Lee Bates' short story, "Growing Up," we might think that the title refers at first to the ladies' puppy, Sigurd—his training and "growing up."
When the women get him as a puppy, Sigurd changes their quiet, stoic lives and brings them joy and hours of entertainment. Sigurd is like a child, and the women grow to love him greatly over time. They know what games he likes to play; they know how to keep him busy on a rainy day: by putting a "cooky" under many wrapped layers while he fights through to the center to take his "prize." Joy-of-Life considers his training to be a serious effort, while the narrator finds more humor in these efforts than necessity—but they try their best to teach him to behave (though sometimes they are like doting mothers). For example, they place a trash can on the dog's head when he knocks it over and spreads its contents all over the floor. While Sigurd understands their intent, he can never quite stop dumping the can. However, he is sensitive enough to understand a scold and to "beg" for forgiveness, and they love him enough never to withhold that forgiveness.
Sigurd comes to love people, especially women. He makes a special show of welcome and affection for all who come to visit. The older the woman is, the more sincere his obvious devotion is.
...but the romance of life centered for Sigurd in old ladies. The whiter the hair, the more beautiful. For them he would spring up on his hind feet and rest his forepaws on their shoulders, pressing his face against their cheeks...
However, he does not like anyone who acts in a secretive manner.
His prejudice had to do, apparently, less with [the tramps'] looks and even their smell than with something stealthy and furtive in their approach. Skulking he abhorred.
However, like a younster, these women forget that Sigurd is a dog, here with them only a short while—that he (like all dogs at a time without vaccinations) is an easy mark for canine illnesses. When he becomes sick, the vet has no answers for them. Sigurd's condition worsens, improves and worsens again, for a long time. He can sometimes be lured out of his discomfort with special treats, or with strokes from his "old mistress," the Lady of Cedar Hill. When she comes for a visit, he rouses himself upon hearing her voice, uttering a weak cry.
Faint and hoarse though it was, there was the old glad recognition in it, and his first mistress, forgetting her intended precautions for the dogs at home, knelt down beside her Njal, comforting him with tender strokes and soft, caressing words.
Wiser people may caution those of us who love dogs to remember that they are "only" dogs. Perhaps this "wisdom" comes to prepare us for the ultimate separation when our dear canine friend dies, for they are so often like members of the family, with their own personalities, that we cannot but give up our hearts to them. The title "Growing Up" refers to the knowledge we come painfully upon when we learn one of life's very difficult truths. In this case, these women—educators—have students, but no children of their own. Sigurd becomes like their child.
The lesson they learn does apply to the brevity of a dog's life—but perhaps (Bates may be saying) they learn also—as a thirteen-year-old might not—that life is short for all creatures, not just dearly loved dogs. Love is a beautiful and sometimes fragile thing, regardless of whether it pertains to a dearly-loved person or a dearly-loved dog—like Sigurd.