Abstract: An apparatus for dyeing the skeletons of animal fetuses with medical liquids includes a treating tank for accommodating a cage in which the fetuses are put, in which tank the medical liquids are circulated by a medical liquid pump. When fed into the treating tank, the circulating medical liquids are dispersed over the liquid surface. The skeleton-dyeing apparatus further includes a neutralization tank for neutralizing used-up medical liquids discharged from the treating tank.

Abstract: An automatic dyeing apparatus has a casing, a plurality of vessels arranged in the casing, a specimen cage transporting mechanism and a controller capable of moving each cage with a plurality of pieces of slide glass to a predetermined position whereby various dyeing operations can be carried out at the same time.

Abstract: An apparatus for automatically pretreating and paraffining biological specimens in a single vessel for the preparation of specimen blocks to be microtomed into thin slices for microscopical study. A rotary selector valve assembly with a built-in gate valve placed a plurality of reagent vessels, containing various reagents including molten paraffin, in and out of communication with the processing vessel in a prescribed sequence. An air pump coacts with directional control valves to evacuate the processing vessel for drawing the successive reagents into same via the rotary selector valve assembly and to deliver gas under pressure into the vessel for the discharge of the reagents therefrom back into the respective reagent vessels. For automating the apparatus a level sensor is provided to the processing vessel in order to close the gate valve and to set the pump out of operation whenever a reagent is drawn into the processing vessel to a predetermined level.