Mushroom tray

Claim 1

A TRAY FOR USE IN MULTIPLICITY TO EXPOSE SUBSTANCES TO SELECT AMBIENT ENVIRONMENTAL CONDITIONS, AS IN THE GROWTH OF MUSHROOMS, COMPRISING: A PLURALITY OF UPRIGHT POSTS INCLUDING FOUR CORNER POSTS POSITIONED TO DEFINE THE CORNERS OF A RECTANGLE, SAID POSTS HAVING AN UPPER END SUBSTANTIALLY VERTICALLY ABOVE A LOWER END; A PLURALITY OF FOUR ELONGATE SIDE RAILS HAVING UPPER AND LOWER EDGES, AND EXTENDING PERPENDICULARLY BETWEEN SAID CORNER POSTS AND BEING AFFIXED THERETO TO HOLD SAID POSTS UPRIGHT, SAID SIDE RAILS BEING AFFIXED TO SAID CORNER POSTS WHEREBY THE UPPER EDGES OF SAID SIDE RAILS ARE SUBSTANTIALLY THE SAME DISTANCE FROM THE UPPER ENDS OF SAID CORNER POSTS, AS THE LOWER EDGES OF SAID SIDE RAILS ARE FROM THE LOWER ENDS OF SAID CORNER POSTS, AN APERTURED BOTTOM SUPPORTED BY SAID RAILS WHEREBY TO CARRY SAID SUBSTANCES FOR EXPOSURE; AND MATING MEANS AFFIXED TO SAID CORNER POSTS AND SAID SIDE RAILS WHEREBY A MULTIPLICITY OF SAID TRAYS MAY BE ALTERNATELY STACKED IN A FIRST MANNER WITH THE UPPER ENDS OF THE POSTS OF A FIRST TRAY ABUTTING THE LOWER ENDS OF THE POSTS OF A SECOND TRAY, AND IN A SECOND MANNER WITH THE UPPER ENDS OF THE POSTS OF A FIRST TRAY ABUTTING THE LOWER EDGES OF THE SIDE RAILS OF A SECOND TRAY.