PROPAGATION BY MEANS OF SEEDS AND SPORES 29 



FIG. 15. Spr outing-cup. 



seeds, and is kept moist by capillary attraction; a glass cover (a). 



The apparatus is seen set up in Fig. 14. This device works 



on a principle long utilized in the 



testing of seeds the capillary 



power of earthenware and various 



species of rock and there are 



many applications of the idea in 



practice. These seed-testers may 



be placed in an incubator or 



other heating device, or they may be used in the greenhouse 



or a living-room. 



A bulletin (No. 35) of the Rhode Island Experiment Station 



describes and illustrates a modification of the absorbing-block 



idea (Fig. 15). Instead of a slab of stone or earthenware, 



"sprouting cups" are used. "They are 3 inches in diameter 



and If inches high, including the cover, which is ventilated. 



The bottom is solid and -J inch thick. Each cup is placed in* a 



glass dish in which a constant supply of water is kept." These 

 cups are placed in a " sprouting-chamber " 

 (Fig. 16), supplied with uniform heat. 

 "This holds about fifty cups. Heat is 

 supplied by a gas jet, which is supported 

 beneath the chamber, and it is distributed 

 evenly to all sides of the chamber, except 

 the front, by means of a water-jacket. 

 It is provided with two doors, the inner 

 one being glass. There is an opening in 

 the side and top for ventilating, and a 

 second opening in the top for the inser- 

 tion of a thermometer. There are also 

 two openings into the water-jacket at 

 the top. In one of these a thermostat 

 (c) is placed, which controls the flow of 



16. Sprouting- . ' 



chamber. gas at the jet beneath, and in the other a 



FIG. 



