_To the teacher._--Require the pupils to observe the special structure that facilitates the dispersal of the seed. As an illustration, ask the pupils to find the seeds of the burdock and to describe what the burr is really like. They find that the burr is a little basket filled with seeds. The basket has many little hooks which catch on the hair of animals and, since these hooks turn inwards, they serve to hold the basket in such a position that all the seeds are not likely to drop out at one time. The pupils should also observe that these baskets are quite firmly attached to the parent plant until the seeds are ripe; after that the baskets break off the plant at the slightest pull. SEED COLLECTIONS During late summer and in the autumn the seeds of the weeds that have been identified by the pupils should be collected. Instruct the pupils to rub the ripened seed pods between the hands until the seeds are thrashed out, at the same time blowing away the chaff. The seeds are now placed in small phials or in small envelopes and these are carefully labelled. If possible, fill each phial so that there may be sufficient seed for use by all the members of the class in the lessons on seed description and identification which are to be taken during the winter months, when Nature Study material is less plentiful than it is in the summer and autumn. The phials or envelopes may be stored in a shallow box, or the phials may be mounted on a stout card. They may be attached to this card either by stout thread sewed through the card and passing around the phial, or by brass cleats, which may be obtained with the phials from dealers in Nature Study supplies. MAN AS A DISPERSER OF SEEDS Man as an agent in the dispersal of seeds should be made a topic for discussion. Obtain, through the pupils, samples of seed-grain, clover seed, timothy seed, turnip seed, etc. Ask the pupils to examine these and count the number of weed seeds found in each. The results will reveal a very common way in which the seeds of noxious weeds are introduced. Describe the introduction from Europe to the wheat-fields of the Prairie Provinces of such weeds as Russian thistle, false-flax, French-weed. The seeds of these weeds were carried in seed-grain, fodder for animals, and also in the hay and straw used by the immigrants as packing for their household goods. Careful farmers will not allow thrashing-machines, seed drills, fanning-mills, etc., to come from farms infested with noxious weeds to do work upon their farms, nor will they buy manure, straw, or hay that was produced on dirty farms. THE SUGAR MAPLE FIELD EXERCISES