Teachers' Leaflet. 469 



collar is made of the anthers. When the cape is removed the body is 

 seen to be the ribbed seed pod. 



THE MILKWEED. 

 LESSON XXXIV. 



THE MILKWEED POD AND ITS CONTENTS. 



Preliminarv Work. — A milkweed plant near the schoolhouse is the best begin- 

 ning of this subject. The mechanism of the milkweed flower is so complex, that 

 the study of it belongs to the high school nature work. In studying the plant the 

 most obvious peculiarity is the milky juice which flows from any wound. This 

 juice is not sap, but a special secretion which probably serves two purposes; it 

 is acrid and disagreeable to the taste, and very few grazing animals can be induced 

 to touch it. The milk coagulates and dries very quickly and thus may serve to 

 heal the wound in the plant and keep out microbes. In studying the milkweed 

 compare it with the rubber tree, and make it the basis of a geography story. After 

 the pupils know the plant, lead them to notice the following things. 



Purpose. — To give the pupil a comprehension of nature's economical 

 way of putting up seed packages. 



Material. — A milkweed pod nearly mature and unopened. 



Observations. — Note how we open the pod by pulling it apart along 

 the seam. Note that this is not a raw edge but it is like selvage. A 

 little later as the pod dies it will break open of its own accord along this 

 seam. Note the rough outside of the pod and the smooth, glossy lining, 

 while between the two is a cushion of coarse fibre, and all of this is for 

 the protection of the precious seeds. As the pod is opened notice that 

 within it is something that looks like a fish covered with scales and with a 

 white, silky tail. This is attached to both ends of the pod, but the stronger 

 attachment is at the stem end. Note that the seeds overlap each other 

 in oblique rows ; an arithmetic lesson may be given by counting the 

 seeds in a row and inultiplying. Lift out one seed, the silk which later 

 makes the balloon lies together like a waxed thread. An interesting 

 subject for a lesson is the action of this silk. Place a seed with the silk 

 attached in the sunshine, the seed lying flat on the table. Very soon the 

 fibers of the silk will begin to separate and curl back, and will soon lift 

 the seed into an upright position. In a minute or two each delicate fiber 

 will have moved off by itself as if it were alive, and the balloon is complete 

 ready for the first wind that blows. Take this fish-like body from the 

 milk-weed pod and remove the seeds one by one, taking off first the top 

 row and then the one beneath, and thus unravel this seed and silk 

 package and learn to adinire the perfection of its arrangement. 



Experiment. — Drop a milkweed balloon on water ; note that it will 

 float for a time and that after the silky fibers become matted in the water, 



