DO PLANTS HAVE INSTINCT. 



Instinct has been defined as a sponte- 

 neous impulse, especially in the lower 

 animals — that moves them, without rea- 

 soning, toward actions that are essential 

 to their existence, preservation and de- 

 velopment. Instinct, imbedded in their 

 organic structure, is the guide of animal 

 life as reason is the guide of rational life. 

 Instinct is said to be incapable of devel- 

 opment and progress. 



It is instinct that guides the wild goose 

 in his long flight to meet the changing 

 requirements of food and nesting. It is 

 instinct that enables the carrier pigeon, 

 though taken hoodwinked and by night 

 to distant points, to wing his way uner- 

 ringly homeward. Instinct leads the 

 thrifty squirrel to stock his larder with 

 nuts in anticipation of the period that 

 must pass ere nuts are ripe again, and 

 teaches him to destroy the embryo plant 

 by biting out the germ so that his chest- 

 nuts will not sprout and thus be spoiled 

 for food. The same wonderful power en- 

 ables the bee to build her comb upon the 

 strictest mathematical principles so as to 

 obtain the greatest storage capacity and 

 strength of structure with smallest con- 

 sumption of wax, and then to store it with 

 one of the most perfect and concentrated 

 of foods. These and many other well- 

 known cases of animal instinct will occur 

 to the reader, but the object of this article 

 is to mention a few phenomena of plant 

 life, whereby they make, what we should 

 designate in human beings, an intelligent 

 adjustment to environment or provision 

 for their future life and development. 



As autumn approaches, even before 

 Jack Frost strikes the first rude signal 

 for winter quarters for insect and plant, 

 or the wintry blasts compel the trees to 

 furl sail and scud under bare poles, the 

 forest trees begin to prepare for unfavor- 

 able conditions by forming and securely 

 tucking away the bud that is next year to 

 develop into leaf and flower. Before the 



leaf drops ofif, a substantial layer of cork 

 is made to close up the pores through 

 which the sap had so freely flowed during 

 the growing season. 



My older readers know, of course, that 

 the green color of the leaf is due to the 

 numerous corpuscles of chlorophyll 

 which fill the cells. This same chloro- 

 phyll has an important mission to fulfill. 

 These little green bodies are the only real 

 food-making machines in nature. Upon 

 the product of these tiny mills all animate 

 nature depends for food. Their motive 

 power is light, and their raw material the 

 inorganic fluids absorbed by the roots 

 from the soil, and their product is sugars 

 and starches. It will be seen that chloro- 

 phyll is one of the most precious, as well 

 as one of the rarest of substances, for 

 while there may appear a great quantity 

 it is superficial, never entering deeply 

 into the substance of the plant. 



The trees, by a sort of instinct, shall 

 we say, withdraw their cohorts of green- 

 liveried workers from the front as au- 

 tumn approaches and deck themselves in 

 the more gaudy but less wholesome col- 

 ors of declining life. It is after the chlo- 

 rophyll is withdrawn that the layer of 

 cork is formed. The sturdy oak usually 

 holds his brown leaves until they are 

 whipped ofif by the wind. 



The plants have been using light as a 

 motive power for ages, while man, with 

 his much-vaunted reason, is just begin- 

 ning to utilize the kindred force, elec- 

 tricity, in arts and sciences. Man makes 

 light draw a few pictures in sombre black 

 and white, while nature flings broadcast 

 landscape and life scenes in varied tints 

 and shades. 



In the process of photosynthesis much 

 more energy is received than is necessary 

 to run the machinery, so the plant, with 

 commendable frugality, uses it in laying 

 on what botanists call warming-up colors. 

 If you will notice the peach twigs the next 



162 



