ERRATA 
Page 176, Table I, for the sixth line of figures, 7 8 8 read 
7 2 2. Also below the eleventh line of figures on the left half of 
the table, a new line of figures, 15 6 6, should be inserted. 
Annals of Botany , Vol. XXVI, No. CXLII. April, 1922. 
