330 



The Journal of Heredity 







MOIST CHAMBER GERMINATOR 



Figure 22,. An easily made and efficient germinator for sprouting the delicate Crepis 

 seedlings. It is made by folding a paper towel over a piece of flat glass and letting 

 the ends dip into water. The seeds are covered with an inverted petrie dish. 



for clays in the germinator without 

 sproviting can sometimes be made to do 

 so by splitting the seed coat. The ger- 

 minators should be placed in subdued 

 light, inasmuch as the light tends to 

 retard lengthening of the root and 

 hypocotyl, making it more difficult to 

 get the seedling into the soil proi)erly. 

 The intensity of the light may be re- 

 duced by placing over the germinators 

 several thicknesses of newspapers. 

 Under such conditions the hypocotyl 

 elongates so as to facilitate handling 

 and planting. The achenes will germi- 

 nate under a wide range of tempera- 

 tures but from 60° to 70'^ F. gives most 

 satisfactory results. 



With such small seedlings some diffi- 

 culty may l)e encountered when the 

 watering is done from above when 

 either a hose or sprinkling-can is used, 

 because of soil being washed over the 

 seedling. This may be avoided by 

 placing the pots in shallow pans whiclr 



are then tilled with water. The water 

 enters the pot through the drainage- 

 hole in the bottom and is ■ carried up- 

 ward to the surface by capillary move- 

 ment. For the first few days the top 

 of the pot may be covered with a piece 

 of glass which will check surface 

 evaporation. A relatively small num- 

 ber of pans may serve for a large num- 

 ber of pots inasmuch as the pot needs 

 to remain in the water only ten to 

 twelve hours to be thoroughly irrigated. 

 The pans may then be shifted to serve 

 iti watering another group of pots. 

 When the plants are about four or five 

 weeks this sub-irrigation may be dis- 

 pensed with. 



For field cultures the seedlings can 

 be placed in 2" x 2" x 2" bottomless tar 

 pa])er planting pots ( obtainable at seeds- 

 men's supply houses), and later, when 

 the rosettes start to form, placed in the 

 field rows ; or the seedlings can be 

 placed in flats without using the paper 



