548 Home Nature-Study Course. 



Facts for the teacher. — In such a lesson a magnifying glass is of great assist- 

 ance, and it may be had very cheaply — from fifty cents up. But even without one, 

 the pair of woolly, folded leaves, and the spike of undeveloped flowers may be 

 distinguished in the large, terminal buds of the horse-chestnuts. The side buds 

 contain only leaves. The scales overlap each other in opposite pairs on four sides 

 of the twig and seem to be covered with brown varnish which is very sticky to 

 the touch. 



Below each bud on the twig is a scar of horse-shoe-form studded with tiny 

 dots, like nail heads. These show where leaves were attached in a previous season, 

 and the '"nails" indicate the number of leaflets, for they are made by the bundle 

 of fibers which pass through the center of the leaf-stalk, and connect the twig 

 with each individual leaflet. Beside the leaf-scars, the falling away of the bud- 

 scales each year leave ring-like marks which show where they were attached. 

 The difference in appearance between the last section and that which is a year 

 older is very distinct, the bark being darker and the scars less plain. When cut 

 across, the youngest part shows only a woody envelope with a white, pithy center; 

 older sections show annual rings. Many little dots of lighter color than the bark 

 may be observed scattered over the twigs. Under the lens they are seen to be 

 fissnres or openings in the bark. They are the lenticels or breathing pores. 



Some of the largest twigs should be forced in water for the sake of easy 

 observation of the unfolding leaves; their soft coloring, and the swift uplifting 

 of the tiny tents is a sight not soon to be forgotten. 



Our native species the Ohio Buckeye and the Sweet or Big Buckeye, are also 

 beautiful trees and are sor.iewhat common, so that comparisons between them 

 and the immigrant horse-chestnut may be made very interesting. 



References : "The Tree Book," Rogers ; "Guide to the Trees," 

 Lounsberry; "FamiHar Trees and Then* Leaves,'' Mathews. 



THE DAHLIA. 



Preliminary ivork. — Give some history of the flower. It is a native of Mexico 

 and Central America, where it is still an abundant wild flower. It was first grown 

 in Europe in 1789. It was named in honor of Professor Andreas Dahl, a Sv;edish 

 pupil of Linnseus. The first cactus dahlia was grown about forty years ago from 

 a Mexican tuber which had been imported by a Dutch dealer in bulbs. It was 

 named for President Juarez of Mexico, and from that one plants all others of the 

 kind are descended. 



LESSON XXI. 



THE PLANT. 



Purpose- — To draw the observation of the pupil to the fact that plants 

 are related to each other, and that very gorgeous ones often have homely 

 relatives that may be harmful to man's interests. 



Material. — An entire plant with tuber attached, if obtainable ; if not, 

 one or two "toes " may be taken without injury to the plant by digo;ing 

 down and carefully cutting them away without stirring the main clump. 

 Some of the dahlia's poor relatives, like the wild sunflower and the pitch- 

 fork weed, should be brought in for purposes of comparison. 



