178 



SUGAR BEET SEED. 



are counted as usual after the prescribed interval 

 of seven days. 



In France, it is proposed to use porous earthen 

 plates; rich vegetable soil is used as a germinating 

 medium. It appears that earth, such as collects in the 

 trunks of old trees, offers special advantages. The 

 spacing between seed is determined by the use of a wire 

 cloth with I c. m. (one-third of an inch) mesh; a seed 

 is placed in the centre. The large seeds are kept sep- 

 arate from the small; these are then covered with 2 

 to 4 m. m. earth. These dishes are kept in a 

 warm place in the laboratory, and the earth is moist- 

 ened with rain, or distilled water, at regular intervals. 



Fig. 54. Arrangement of seed. 



-3 + 1 = 25 



3 + 6 + 5 + 4- 



It is recommended not to use too much water, so as to 

 avoid mildew. 



The Maercker method is also interesting. Ordi- 

 nary porcelain plates are used; these are filled with cal- 

 cined sandy quartz, and about 40 per cent, water is 

 necessary for the preparation of the layer, or 100 c. c. 

 for 500 c. c. of sand. The circular surface is divided 

 into four equal sectors, to facilitate the counting. In 

 each sector two rows of six seeds are arranged, and 

 alongside of them other rows containing five, four, 

 three and one seed respectively, or a total of twenty- 

 five seeds for a sector, meaning 100 seeds per plate 



(Fig. 54). 



