S60 STATE HORTICULTURAL SOCIETY 



the reports the teacher thinks best to send, or a summary of them, and if 

 any ask questions I shall do my best to answer them. Can any one tell 

 how or why these leaflets of clover behave as they do? 



As loDg ago as you can remember, you knew that all animals of the 

 farm moved about of their own accord in every direction, but most likely 

 you discovered that the plants you saw were unable to go from place to 

 place, and you may not have thought it possible that a stem or leaf or 

 flower should change its position while on the plant. Now that your 

 attention has been called to it, you may remember the fact that the leaves 

 and stems also, of a plant when placed close to a window bend toward the 

 light, and if turned around they will bend again toward the window. 

 They bent so slowly that you couldn't see the motion, but they really 

 moved just as surely as the hour hand of a clock moves. 



You have seen that the leaflets of clover 

 repeatedly take different positions with 

 reference to each other, even within the 

 space of an hour or two, and perhaps 

 yoa may have found out that the leaflets 

 of some other compound leaves are able 



^'c^over "as'^leen 'i^'thl ""■ I?Ve%"n ' a1 tO chaUge their pOSitioUS. 



day time. night. You may have seen that the shape of 



each leaflet of clover was much the same at all times of day and night, 

 but the very short and rather thick stem of each leaflet curved about caus- 

 ing the leaflet to take a different position, sometimes holding it out with 

 one flat side toward the sun, sometimes with one edge to the sun, and 

 usually all three leaflets of a leaf were brought snugly together on cool 

 nights. The leaflets of some plants move upwards, some downwards, or 

 they turn about by a slight twisting of the short stem. In many cases 

 the leaflet? move about in several directions, before getting int) shape for 

 the night or before getting back into the usual place for the day. 



The botanist knows something about the structure of the stems of the 

 leaflets of clover and knows what happens to cause the motion you have 

 discoveied, but it is rather difficult to make plain to young pupils and 

 cannot be well explained in very simple language. We trust you may all 

 understand it some day. Why do the leaflets get together in the cool of 

 the day? Darwin and others found out that leaflets, if fastened by pins 

 and kept spread out in cool nights with one side to the sky, were cooler 

 and had more dew on them than others which crowded together. In cold 

 nights pigs crowd together to keep warm, and so it is believed that the 

 leaflt-ts of clover bring themselves together to keep warm, at least to pro- 

 vent getting very cool. 



If the weather were very bright and hot when some of you looked at 

 the clover, you saw that the edges of the leaflets in many cases turned 

 more or less toward the sun. The reason for this seems to be to prevent 

 damage to the leaflets from extreme heat falling directly onto the surface 

 of the leaf. It also prevents a very rapid loss of moisture from the leaf. 



This cuddling together after the manner of the leaflets of clover is 

 often called the sleep of plants. Though the motion is most rapid when 

 crowding together for the night, or when getting out in early morning for 

 the day, still the leaflets at all times of day and night, as long as they live, 

 are never perfectly at rest, but keep slowly jerking about, a very little at a 

 time, evea though there may be no motion of the air. The leaves of a 

 young cabbage rise at night and fall by day, and even the thick leaves of 



