The Laboratory 75 



with proper filters and correctly placed outlets 

 will provide adequate aeration and temperature 

 control. A room about 8 X 10 ft. with 8 ft. ceiling 

 is an excellent size. The lighting should be dif- 

 fuse, preferably through a broad skylight supple- 

 mented by properly placed indirect lamps. Cup- 

 boards with tight, sliding doors may be built into 

 the walls, but there should be no fixed furniture 

 in the room and all wall surfaces, doors, etc., 

 should be designed so as to reduce to a minimum 

 the possibility of dust accumulating. Outlets for 

 electricity, compressed air, vacuum, and water 

 should be provided. There should be a sink built 

 into a flush hood at one end of the room. A 

 movable table and stools should be provided. The 

 walls and ceiling should be of washable tile or 

 enamel and, as Carrel (see Parker, 1938, 26) has 

 pointed out, a dark gray color is best since it 

 reduces reflections and the mental distractions 

 which lighter-colored surfaces always impose. 

 Provision should be made for washing the air of 

 the room with a series of water sprays or steam 

 jets so as to remove any spores which may get in 

 when the room is opened. 



A transfer room for plant tissue cultures should 

 not contain gas outlets. Gas is extremely toxic to 

 plant materials and unburned gas may easily be 

 occluded in the culture flasks if the mouths are 



