While man is the greatest enemy of the plant world, he is also at times its greatest friend. When it is to his advantage or when he is prompted by a sincere love of Nature, he becomes a strong and helpful ally. He aids his fellow creatures of the vegetable world when they are sick or injured and, by improving their environment and protecting them from attack and danger, enables them to develop to best advantage. A wizard like Luther Burbank helps them in their efforts at race improvement and development. In Egypt and Arabia, man has acted as carrier of pollen for centuries, and has thus insured an abundant Date crop. The same thing is often done in other parts of the world with Apples, Pistachios, Melons, Cucumbers and other plants having unisexual flowers. CHAPTER VI MARRIAGE CUSTOMS OF PLANTS “_Pale primroses That die unmarried._”--_Shakespeare_ “Love consumes the plants” once wrote Linnaeus, and the observation of every student of Nature goes to confirm his statement. The plants marry and are given in marriage. Reproduction is undoubtedly their chief end in life. The simplest and most primitive plants have no sex but produce new individuals by splitting their single cells in two. It is in the thread-like bodies of Pond Weeds that we find the first beginnings of the principle of generation by union. These lowly creatures consist of single cells strung end to end like beads in a necklace. When two of the living chains happen to find themselves parallel to each other, certain of the cells reach out and join those opposite them to form new cells. Such a mixture of life forces is always beneficial to the race. In the higher plants the same process is carried out in a little more elaborate way. Of the two cells which unite, one is small and active, and is called the male or pollen cell. The other is larger, richer and more passive, and is the ovule or female cell. It is one of the main objects of each plant’s life to see that its ovules are fertilized by pollen grains from some other member of the same species. When this is impossible, flowers are reduced to fertilizing themselves, but if this continues very long, degeneracy is very apt to result. It is not wise to marry one’s first cousin. Many plants depend upon the wind to distribute their pollen. Such species bear slight, inconspicuous flowers which not infrequently cluster together in long, pendent catkins. This was undoubtedly the first and original form of plant marriage. Though often successful, it is very wasteful and undependable. “The wind bloweth where it listeth” and loses a million grains of pollen for every one it lodges. One hazy day in the long ago, some plant had a brilliant idea. “There are a number of insects which are in the habit of paying me unwelcome visits for the purpose of eating pollen. Why can’t I make use of these thieves and turn their marauding habits to my own advantage?”