Of course I do not pretend to say that cultivated plants should be expected to be less variable than in the wild state, or that swarms of elementary species might not be produced during cultivation quite as well as before. However the chance of such an event, as is easily seen, cannot be very great, and we shall have to be content with a few examples of which the coconut is a notable one. Leaving this general discussion of the subject, we may take up the example of the beets. The sugar-beet is only one type from among a horde of others, and though the origin of all the single types is not historically known, the plant is frequently found in the wild state even at the present time, and the native types may be compared with the corresponding cultivated varieties. The cultivation of beets for sugar is not of very ancient date. The Romans knew the beets and used them as vegetables, both the roots and the leaves. They distinguished a variety with white and one with red flesh, but whether they cultivated them, or only collected them from where they grew spontaneously, appears to be unknown. [68] Beets are even now found in large quantities along the shores of Italy. They prefer the vicinity of the sea, as do so many other members of the beet family, and are not limited to Italy, but are found growing elsewhere on the littoral of the Mediterranean, in the Canary Islands and through Persia and Babylonia to India. In most of their native localities they occur in great abundance. The color of the foliage and the size of the roots are extremely variable. Some have red leafstalks and veins, others a uniform red or green foliage, some have red or white or yellow roots, or exhibit alternating rings of a red and of a white tinge on cut surfaces. It seems only natural to consider the white and the red, and even the variegated types as distinct varieties, which in nature do not transgress their limits nor change into one another. In a subsequent lecture I will show that this at least is the rule with the corresponding color-varieties in other genera.