SELECTION AND SEQUENCE OF MATERIAL. 309 



have studied snails, and know something about the way 

 in which snail and clam shells are formed. Crystals 

 mean almost nothing until the process of crystallization 

 has been investigated. The dissemination of seeds 

 will mean much more after the children have studied 

 their formation or relation to the plant. When they 

 have discovered how much the plant roots, stem, 

 leaves, flower has done to make the seed, they will 

 appreciate better the various wonderful provisions by 

 the mother plant for insuring the dispersion of her seed 

 babies. The study of falling leaves in the autumn will 

 mean much more if the children see during the winter 

 how useful fallen leaves are in covering and keeping 

 warm the buds and seeds, and the eggs and larvaB of 

 animals, and discover in the spring how leaves enrich 

 the soil by their decay, and how they feed other plants. 



It is essential also that the earlier work should give 

 the children a clear idea of wholes or units to which 

 the parts, studied later, are readily related. It is much 

 better, for instance, for the child to begin with the 

 germination of a plant from the seed, to watch the 

 gradual appearance and development of the parts, 

 root, stem, leaf, flower, and discover the relation, 

 functional and structural, of all parts to the whole and 

 to one another, than to begin with the study of leaves 

 or flowers, all of which are parts, incomplete and sepa- 

 rated from the whole to which they belong, and to 

 which the child cannot or does not relate them. 



It is equally helpful to come back to wholes or units 

 after the study of parts, and so to review and relate the 



