A number of hybrids between the Mexican lime and Genoa lemon were made in 1909 by Walter T. Swingle. Although the Mexican lime was used in these crosses as the female parent, the fruits are more like a true lemon in appearance. The pulp in color, texture, and, to a less extent, in flavor shows the influence of the pollen parent. This fruit had promise for the warm region of the lower east coast of Florida, where it first fruited at Little River, it was proposed to name it in honor of the pioneer horticulturist of this region, Henry Perrine, to whom Congress in 1838 made a large grant of land for planting to tropical plants, and who is reputed, among many other introductions, to have planted seed of the Mexican lime on several of the Florida keys, the beginning of the so-called wild lime groves of this region. This new fruit, a hybrid between the lime he introduced and the lemon, is therefore named the Perrine lemon. Fruit, size and shape of ordinary lemon, although somewhat variable, average fruit 2 3/4 to 3 inches in length by 2 1/4 to 2 3/4 inches in diameter, having abrupt protuberances surrounding' calyx and small nipple at blossom end characteristic of lemon ; pistil often persistent ; color pale lemon yellow (Ridgway barium yellow to pale lemon-yellow) ; rind thin and tough, one-eighth inch, fairly smooth, slightly corrugated or wrinkled; segments 10 to 12 ; small solid, core, thin segment walls, vesicles very small and tender pulp very juicy and translucent, of pale greenish yellow color (Ridgway pale dull green-yellow), suggesting lime; flavor more like lemon than lime, sharply acid with no "off flavor" or after taste ; seeds variable in number, usually 4 to 6, sometimes up to 12, slender and long pointed ; tree evergreen, vigorous, productive, and precocious ; of rather compact habit, resembling the lime in this respect rather than the lemon ; leaves unifoliate, large (3 to 5 inches in length), pointed oval, with short wingless petiole, resembling the lemon leaf. The tree is much more hardy than the lime and appears somewhat hardier than the common lemon ; more or less everbearing, having ripe fruit, fruit in all stages of development, and newly opened flowers at the same time. Juice is developed while the fruit, is still green and immature, in which respect it resembles the lime. The fruit, like the lime, when fully ripe drops to the ground. Outstanding in its behavior under Florida conditions is its resistance, if not complete immunity, to two* of the worst diseases that attack, respectively, the lime and the lemon—lime withertip and citrus scab. In April, 1930, experiments were con-ducted at the United States Citrus Disease Field Laboratory, Orlando, Fla., under the direction of H. R. Fulton, to determine there action of the Perrine lemon to lime withertip. The report of H. E. Stevens, who made these tests, is as follows: Attempts were made to induce withertip on 12 young growing shoots. Active withertip-infected shoots from Key limes were placed in contact with the above under conditions favorable for the disease to develop, but no infections were obtained on any of the shoots so treated. This combination of characters is doubtless due to the fact that the common lemon is immune to lime withertip and the Mexican lime is immune to citrus scab, the hybrid inheriting both immunities. The acid content of the fruit has been found to be 6.39 percent as compared with 5.17 percent in the Villa Franca lemon and 6.89 percent in the Key (Mexican) lime, these percentages representing content of anhydrous citrus acid.