and as it is carried upwards the pollen is secured. [Illustration: Fig. 100. Flower tied up.] The stigma should receive an abundant supply of pollen. No harm can come from supplying too much while if too little is applied, some of the seeds will not mature or even the fruit may not set. It is well known that in many plants, at least, the pollen stimulates the development of the fruit-walls, as well as fertilizes the ovules, and a greater amount of pollen than is sufficient to produce the seeds themselves may therefore exert an important influence. Sometimes it is not necessary to use an instrument to transfer the pollen. If the pollen is copious and adheres to the anther after it is discharged, the anther may be simply rubbed over the stigma. An anther will ordinarily contain sufficient pollen to fertilize several stigmas. The whole surface of the stigma should be covered until it is colored with the pollen. Sometimes it will be found advisable to cut off the corolla from large flowers, if it was not done when the flower was emasculated, to facilitate the labor of applying pollen. The short stigmas of squashes, for instance, can be reached more easily if the corolla is removed, as in Fig. 104. [Illustration: Fig. 101. Bag.] In order to prevent the mixing of pollen, the flowers from which it is to be derived should be covered while in the bud, the same as the flowers designed as the pistillate parents. Otherwise foreign pollen may be deposited upon the anthers by insects or winds. [Illustration: Fig. 102. Squash flower tied up.] As soon as the pollen is applied to the stigma, the flower should be tied up again the same as before. The bag should remain three or four days or a week, until the stigma has died and all danger of another pollination is removed. If the fruit is likely to be destroyed by birds or insects, it should be covered with netting bags as soon as the paper-bags are removed. These bags also serve to mark the crossed fruits, and to catch them if they should drop before the operator is aware. Of course all crosses should be labelled with the names of both parents and the date of the operation. [Illustration: Fig. 103. Pin-scalpel.]