Abstract: A changeable exhibitor comprising a video or script tape movable on vertical guide rollers in a closed loop, a weighted roller freely movable along a substantially horizontal roller path within the interior space of said loop, a disc on one side of the roller, and projections on the side of the tape facing the roller path, said disc and projections cooperating to advance the tape in response to movement of the weighted roller in one direction along the roller path.

Abstract: Apparatus for the display of information comprises an endless band carrying transverse holders each of which carries a plurality of laminae having differently colored front and rear regions. Each lamina may be positioned either to overlap the front region of the succeeding adjacent lamina or to lie behind it so as respectively to obscure or expose this front region. Selection of one or other of these positions of the laminae is secured by passing the band around a pulley of sufficiently small radius so as to spread the holders apart sufficiently for each lamina to be clear of the succeeding lamina and then moving the lamina to one or other position. The laminae may be magnetic and drawn away from the holder by magnets adjacent this pulley into the overlap position. Alternatively the laminae may be driven back against the holder from the overlap position by jets of air.

Abstract: An improved method and apparatus for handling Drosophila including a simplified nozzle adapter designed to cooperate with the porous cellular obstruction plug in the end of a culture container to permit the passage of carbon dioxide gas therethrough to anesthetize the flies therein. After transferring flies to the sorting chamber for completing a selection process, the fly specimens may be simply and readily transferred to other study containers or culture vials through a suction apparatus positioned in the neck or entrance of the container to receive them.

Abstract: A display device arranged to present selectively three different displays. The displays are formed by three sets of display panels with two of the panel sets being selectively movable as a unit relative to the third and movable relative to each other and to the third to provide the selectively different panel displays. Selective movement of the panel sets is effected by a control which, in the illustrated embodiment, includes a camming element which is guided in a plurality of angularly related paths to effect the desired selective disposition of the different panel sets.

Abstract: A self-contained, portable animal commode including a base with a waste holding tank and a top pivoted to the base, the top including an end vertical panel, for satisfying a male dog's natural urinating instincts, and a platform underlying a movable belt upon which the animal stands to urinate and defecate. After the animal steps off the commode, the belt is rotated forwardly to deposit waste in the tank while, simultaneously, the end panel and belt are flushed of waste. Then the belt is reversely driven to its initial position, the belt being wiped clean when moved in both directions.