"Why on earth has Washer given the key to you, Cato?" asked France, looking surprised. "To mind it for her," replied Duane, with a laugh. "You know what a bother there was last year when poor old Washer lost the key in the dinner-hour, and how eventually they had to break open the door and get in. Washer was dreadfully upset and didn't want a repetition of it this year, so she handed the key over to me after we got outside, and asked me to keep it till we went in again this afternoon." There was a general laugh at Duane's explanation. Inside the laboratory Miss Vacher was as keen and as capable as Miss St. Leger herself. Away from science, she was the most hopelessly absent-minded person it was possible to imagine. She kept an army of small girls constantly employed looking around for her possessions. However, everybody seemed to take the explanation for granted, though Kitty _did_ think that the science mistress's eccentricities were responsible for a state of affairs that was not quite what it should be. Still, it was certainly not her place to say so. Duane was eyeing the small messenger ruefully. "Oh, bother Miss Vacher! What on earth does she want a pipette for just before dinner! It isn't soup day. I'm so comfortably settled too, and having a few minutes' rest. I say, kid, if I gave you the key, couldn't you slip along and get it?" The girl looked doubtful. "Better go yourself, Duane," advised Hilary. "You know the lab's out of bounds to-day for us folk. I shouldn't send a junior, in case of an accident." "No, I suppose not," agreed Duane. "I shouldn't like to get anyone into trouble. Still, it's an awful bore," and she yawned as she spoke. "I'll go if you like," Kitty volunteered. "I know where the pipettes are kept--over by the window--and it won't take me a minute." "Thanks ever so much," said Duane. "You're a brick. Here's the key. Of course, there's no need to advise you to give a wide berth to our experiments." "Of course not," replied Kitty. "I shan't go near the benches. I'll be back in a tick." She disappeared with a nod, and in a few minutes returned and handed over pipette and key to Duane, who slipped the key into her pocket and gave the pipette to the junior. "Here you are. Trot it along--with Duane's love--and don't smash it on the way. Be sure you don't forget the love." "Vacher was always rather smitten with you," remarked Bertha with a grin. "Now, any of the others would have handed the key over to Salome. She's your senior really." "Yes, queer taste on Washer's part, isn't it?" returned Duane complacently. "Very," said France, bursting into a laugh. "However, you make a very well-matched pair." "Yes, I suppose you're thinking that opposites meet," replied Duane, undisturbed. "There's only one thing in which Washer and I are alike." "What's that?" "Our genius for science."