700 



Handbook of Nature-Study 



nothing but "trimming," they are so purely ornamental. Each little cup 

 or socket, of the joint or node, in branch or stem, has a row of points 

 around its margin, and these points are terminals of the angles in the 

 branch. If a branch is triangular in cross section, it will have three 

 points at its socket, if quadrangular it will have four points, and the main 



stem may have six or a dozen, 

 or even more points. The 

 main stem and branches are 

 made up entirely of these seg- 

 ments, each set at its lower end 

 in the socket of the segment be- 

 hind or below it. These green 

 branches, rich in chlorophyl, 

 manufacture for the plant all the 

 food that it needs. Late in the 

 season this food is stored in 

 the rootstocks, so that early next 

 spring the fertile plants, nour- 

 ished by this stored material, are 

 able to push forth before most 

 other plants, and thus develop 

 their spores early in the season. 

 There is a prothallium stage as 

 in the ferns. 



Above where the whorl of 

 stems comes from the main 

 branch, may be seen a row of 

 upward-standing points which 

 are the remnants of leaves ; each 

 branch as it leaves the stem is set 

 in a little dark cup with a toothed 

 rim. There is a nice gradation 

 from the stout lower part of the 



The sterile plant of the field horsetail, stem to the ^P. which is as deli- 



one-half natural size. cate as one of the side branches. 



The rootstock dies out behind 



the plant and pushes on ahead like the rootstock of ferns. The true 

 roots may be seen attached on the under side. The food made in the 

 summer is stored in little tubers, which may be seen in the rootstocks. 



LESSON CLXXVII 

 THE FIELD HORSETAIL 



The Fertile Plant 



Leading thought The horsetail is a plant that develops spores instead 

 of seeds, and has green stems instead of leaves. 



Method In April and May, when the children are looking for flowers, 

 find some of these weird looking plants. These should be 

 brought to the schoolroom and the observation lesson given there. 



Observations i. Where are these plants found? On what kind of 

 soil? 



