Air layers are a variation of the common type of rooted cuttings. In preparing an air layer, the forester girdles a branch through the bark and cambium and surrounds the girdle and 4 to 6 inches of stem above the girdle with moist sphagnum moss enclosed in a plastic bag.

At Lake City, Fla., Francois Mergen obtained 85 percent success in rooting branches of slash pine (Pinus elliottii). He treated the girdle with indolebutyric acid. Roots appeared within 6 weeks on branches on which air layers were installed in August.

Needle fascicles are potentially a great source of plant material for vegetative propagation. The fascicle can develop a shoot; the bud arises inside the needle bundle in pines. In species having only a single needle, as the firs and spruces, a bud may arise from the axil of the needle. When they are detached from a branch and placed in a rooting medium, needle fascicles will root and occasionally develop shoots. Procedures for consistently obtaining root and shoot development have not been worked out. B. Zak, of the Southeastern Forest Experiment Station, has caused roots and shoots to be formed on needle bundles of slash pine and roots alone on bundles of shortleaf pine (Pinus echinata).

GRAFTING of forest trees does not differ from procedures in use for horticultural plants. The veneer graft and the cleft crown graft are the types used most commonly when the scion is detached.

For approach grafting, the bottle graft was used successfully in a plantation of slash pine selected for high yield of gum in Florida. In this method, the end of the scion is kept in a bottle of water until the tissue of the scion and stock unite. Dormant scions commonly are grafted upon active rootstocks. In forestry practice, this requires that cuttings are taken during the winter and kept under refrigeration until the stock trees are active.

Fall grafting is successful, however, as demonstrated with spruce by Hans Nienstaedt, of the Northern Institute of Forest Genetics, Rhinelander, Wis. Succulent tissue grafting makes possible a much longer period in which grafts can be made. Furthermore, the union between the stock and scion appears to be stronger than occurs when the scion is of year-old tissue.

Plastic or paper bags are used to protect grafts made in the forest. A combination of a plastic bag and a paper bag has given the best protection in several trials.

DISTRIBUTION of new trees produced by the Forest Service may be made directly to planters of forest trees or through State forestry agencies.

The McSweeney-McNary Act authorized the Forest Service to enter into cooperative agreements to further research in subjects of mutual interest.

The Forest Service may send newly developed trees for foundation stock to individuals, associations, private nurseries, industries, or public agencies that agree to cooperate in research on the tree.

Several thousand persons, for example, obtained cuttings of hybrid poplars grown by the Northeastern Forest Experiment Station in Pennsylvania. Each recipient agreed to furnish the station information about the survival and growth of the poplars he received. The station thereby furthered its research on the hybrid poplars, and the people received new trees, which could furnish cuttings for greatly expanding production of desirable hybrids.

Similarly, a mining company agreed to plant certain pine hybrids on its holdings to help determine whether the hybrids would thrive in the locality where the company operated.

Exchange of seed or seedlings with public agencies is authorized by the Granger-Thye Act. The Forest Service can furnish public agencies, such as forest schools, State forestry departments, and experiment stations, seeds or seedlings of newly developed trees if the Forest Service receives in return property (seed or seedlings, for example) of equal value.

State nurseries, operating under the provisions of the Clarke-McNary Act, undoubtedly will supply most of the new trees for planting on State and private lands in the future. Under the provisions of this act, the Forest Service may provide seed or trees to the nurseries. The ordinary value of the material is credited to the Federal Government's share in operating the nursery. A Clarke-McNary nursery may then sell the trees it grows to forest planters in line with its policy of providing trees at reasonable cost.

The following situation illustrates how this would work out. At the Lake City Research Center in Florida, forest geneticists selected and bred trees that yield twice the average amount of gum for naval stores. They demonstrated that the tendency was an inherited characteristic. Cuttings of these trees may be made available to State nurseries, as in Florida and Georgia, whose foresters would use the cuttings in developing seed orchards. Seed would be produced in about 10 years. This seed would then be sown in the nursery to grow superior gum-yielding pines for tree farmers and forest industries.

The Forest Service produces superior trees in its nurseries for planting in the national forests. In California, hybrid seed of Jeffrey pine (Pinus jeffreyii) and Coulter pine (P. coulterii) and of knob-cone pine (P. attenuate) and Monterey pine (P. radiate) have been produced in quantity by controlled pollination. Seed will be sown in the Forest Service nursery near Placerville to produce hybrid trees for planting in the national forests.

H. A. FOWELLS has been a member of the Division of Forest Management Research, Forest Service, Washington, D.C., with assignment to the fields of genetics and physiology, since 1954. He entered the Forest Service in 1934.