SEEDLINGS. 13 



and leaves of the plant. The leaves that first appear are 

 almost invariably quite unlike the cotyledons. They are 

 usually the typical or ordinary foliage leaves of the species. 

 In some cases, however, they are mere scales, as seen in the 

 Pea, Oak, etc. The first one or few leaves that appear are 

 usually simpler than those developed later. They may be 

 simple if the typical leaves are trifoliate, or trifoliate if the 

 foliage is pinnate, etc. If the species has lobed or palmate 

 leaves, the first one or more developed are usually entire or 

 heart-shaped. Of as simple type or pattern as the first leaves 

 generally are, they are by no means so nearly uniform in 

 shape and appearance as the seed-leaves. In reference to the 

 latter a writer has said that " Cotyledons are a survival of the 

 universal foliage of deciduous trees in olden geologic days, 

 ere time had differentiated them into their present varied 

 forms." 



B 



