BOTANICAL DEPARTMENT. ^ 251 



•selves, but June grass and some other grasses and weeds soon crept in and 

 partially occupied the ground, apparently retarding considerably the growth 

 of the trees. The grasses and weeds which seem to do the most harm are 

 capable of growing late in autumn and early in spring, while there is no 

 foilage on the trees to shade the ground or plants below. 



The trees where slightly crowded show a marked difference in their habit 

 of holding their lower leaves. The lower branches of black walnut, butternut 

 and white ash die young, because they do not carry their leaves. The tops are 

 thin, allowing sunlight to pass through to the ground and light up grasses, 

 weeds and other undergrowtli. On the contrary, white oak, swamp white oak, 

 beech, sugar maple, dogwood, hazel, blue beech, choke cherry, poplars, and 



. sprouts and seedlings of many others hold their lower leaves well. Some of 

 the evergreens, such as white pine, arbor vit^e, red cedar and Norway spruce, 

 also hold their lower leaves well. To save the expense of cultivation after a 

 few years and to keep the grass out we need to know the best nurses, i. e., 

 the trees, shrubs or herbs which hold their leaves well in the shade. Forest 

 leaves where deep enough keep out the grass, but the wind drives most dead 

 leaves out of the arboretum. To get a few points on this topic of nurses, in 

 October last I made quite a complete list of the broad leaved undergrowth of 

 the arboretum. This included some 60 species. Some of those holding their 

 leaves best, not forgetting those named above, are black cap raspberries, com- 

 mon milkweeds, desmodium, celandine, wild asters, golden rods, grape vines, 

 seedlings of many trees or shrubs, such as black cherry, American elm, bitter- 

 nut, low willows, catalpas, birches and box elders. 



It may not be out of place here to notice some other peculiarities of the un- 

 dergrowth. The lot now called the arboretum has been cleared apparently 25 

 years or more, and the nearest forest is mainly of white and black oak, about 

 30 rods to the northeast. We will except a sma'l piece on the west, separated 

 by a board fence. This lot contains bearing trees of swamp white oak, beech, 

 hickory, bitternut, blue beech, hawthorn, white ash, sugar maple, black 

 cherry, aspen, large toothed aspen, irouwood and American elm. Among 

 the undergrowth are three kinds of oak, black cherry, sugar maple, beech, 

 American elm, bitternut, hawthorn, sassafras, two dogwoods, white ash, spiraea, 

 blue beech, gooseberry, willow, two sorts of grapes, Virginia creeper, also catalpa 

 eleven rods southw st of bearing trees in the arboretum ; white birches ten rods 



• southwest of bearing trees ; box elder four rods west of bearing trees; three 

 sorts of poplars, hazel, ironwood, several sorts of willows, prickly ash, vibur- 

 num, elder, and very likely others. 



From some experiments I find acorns of black oak in the soil did not remain 

 alive for three years. Some of the seeds of the above plants I know are freely 

 spread by the wind, as they have repeatedly been seen on the move. Squirrels 

 I know carry some of the nuts and cover them. I have seen, wliile in tlie ar- 

 boretum, a blue jay drop a good acorn. He has a peculiar hibit of tucking 

 acorns and beech nuts into cracks and corners of the bark of trees and stumps, 

 and very likely forgets to return for them. Woodpeckers and crows are known 

 to carry nuts and seeds and hide or drop them. Many birds we know cat 

 berries and other fruits aid scatter the undigested seeds where they may grow. 

 The young oaks and bitternuts show that they started from nuts in the soil or 



■on the surface, as the remains of the nuts are still to be found. 



Additional studies will no doubt bring forth still more evidence in regard to 

 the manner in which seeds are carried from one place to another, and make it 



