y» 84 FOUNDATIONS OF BOTANY 
sedges, the grasses, and some other plants, there is but one 
cotyledon. Upon these facts is based the division of most 
flowering plants into two great groups: the dicotyledonous 
‘ plants, which have two seed-leaves, and the monocotyledon- 
ous plants, which have one seed-leaf. Other important 
differences nearly always accompany the difference in 
number of cotyledons, as will be seen later. 
' 46. Tabular Review of Experiments. — Make out a 
table containing a very brief summary of the experiments 
thus far performed, as follows: 
NUMBER MATERIALS OPERA- 
OBJECT r 
OF AND TIONS RESULTS’ | INFERENCES 
SOUGHT : 
EXPERIMENT APPARATUS | PERFORMED 
47. Review Sketches. — Make out a comparison of the 
early life histories of all the other seedlings studied, by 
arranging in parallel columns a series of drawings of each, 
