Now Jack had been as well known to Betty as she to him since the days of the long-ago house-party.  When he made his brief visit to The Locusts just before she left for Warwick Hall, they had met like old friends, each familiar with the other’s past Unquestioningly she had accepted Papa Jack’s estimate of him as the squarest young fellow he had ever met—­“true blue in every particular, and a hustler when it comes to bringing things to pass.”

Now for five months Mary had talked of him so incessantly, especially while they were visiting Joyce, that Betty had it impressed upon her mind beyond forgetting, that no matter what else he might be he was quite the best brother who had ever lived in the knowledge of man.  In answer to her cordial little note of acknowledgment came a letter explaining in a frank straightforward way why he had kept her picture, and how he longed sometimes for the friendships and social life he could not have in a little mining-town.  And because there was a question in it about Mary, asking the advisability of her taking some extra course she had mentioned, Betty answered it promptly.

Thus it came about without her realizing just how it happened, that she was drawn into a regular correspondence.  Regular on Jack’s side, at least, for no matter whether she wrote or not, promptly every Thursday morning a familiar looking envelope, addressed in his big businesslike hand, appeared on her desk.

February came, not only with its George Washington tea and Valentine party, but musicales and receptions and many excursions to the city.  No day with any claim to celebration was allowed to pass unheeded.  March held fewer opportunities, so Saint Patrick was made much of, and Mary’s sorority planned a spread up in the gymnasium in his honour.  She had never once mentioned that her birthday fell on the seventeenth also, not even when she first proudly displayed her bloodstone ring, which they all knew was the stone for March.

Nobody would have known that she had any especial interest in the date, had not Jack mentioned in one of his letters to Betty that Mary would be seventeen on the seventeenth, and he was afraid that his remembrance would not reach her in time, as he had forgotten the day was so near until that very moment of writing.

The whisper that went around never reached Mary.  She helped decorate the table with sprigs of artificial shamrock and Irish flags, hunted up verses from various poets of Erin to write on the little harp-shaped place cards, and suggested a menu which typified the “wearin’ o’ the green” in every dish, from the olive sandwiches to the creme de menthe.  To further carry out the colour scheme, the girls all came in their gymnasium suits of hunter’s green, and the unconventional attire tended to make the affair more of a frolic than the elegant function which the sorority yearly aspired to give.

A huge birthday cake had been ordered in the jovial saint’s honour, but nobody could tell how many candles it ought to hold since no one knew how many years he numbered.  But Dorene solved the difficulty by saying, “Let X equal the unknown quantity, and just make a big X across the cake with the green candles.”