September 5, 1894.] 



Garden and Forest. 



359 



take a great deal from the soil. I can testify from an expe- 

 rience of many years that this habit of suckering is confined 

 to trees which have been cut down. The suckers appear 

 a hundred feet from the stump. This seems to show that the 

 tree is one of that kind that has innumerable adventitious buds 

 in the roots, which at once sprout when the trunk is cut off. 

 Like the Sassafras, it will renew itself at once if permitted, and 

 with wonderful rapidity. 



Philadelphia, Pa. 



R. C. McM. 



Hovenia dulcis. 



To the Editor of Garden and Forest : 



Sir, — In reply to Mrs. Dandridge's inquiry about the fruiting 

 of Hovenia dulcis, I would say that some five years ago fruit 

 of this plant was received here from the nursery of the late 

 W. D. Brackenridge, Govanstown, Maryland, where a plant 

 had been fruiting for several years. The large specimen tree 

 on our grounds is in fruit now, as it was last year. 



Germantown, Pa. Joseph Meehan. 



Meetings of Societies. 



American Forestry Association. — II. 



PROFESSOR F. H. KING, of the Wisconsin Experi- 

 ment Station, gave an illustrated account of some 

 observations on the destructive effects of winds and the 

 protection afforded by woodlands and shelter-belts. With- 

 out quoting the tables, we give the leading points of this 

 instructive paper : 



WIND-BREAKS. 



We have in Wisconsin large tracts of land with soils of a 

 light sandy character which give fair yields of excellent pota- 

 toes, but the clearing of these lands in large fields has dis- 

 closed the fact that they are liable to serious injury from the 

 drying and drifting action of the winds. 



After a rainfall of three-fourths of an inch on the 5th and 

 6th of May last the fields in one of these sections which was 

 visited on the 7th had already drifted badly, and on the morn- 

 ing of the 8th the top soil, loosened by harrow, seeder and 

 drill, had been so completely driven from many fields as to 

 leave the grain kernels entirely naked, with the plants lying 

 flat upon the ground, hanging by their roots and whipping in 

 the wind. In many other fields, where the drifting had 

 not been so bad, the Oats, which at the time stood about 

 eight inches high, were cured like hay close to the ground, 

 and even the leaves of Dock Sorrel, which in places stood 

 among the grains, were blackened and so dry as to crumble 

 in the hand. Some exposed eighty-acre fields of grain seeded 

 to Clover were about ruined, the loose soil having been re- 

 moved so entirely that the marks of the bottom of the shoe- 

 drill could be seen over entire acres of ground. But the point 

 to which special attention is invited here is that wherever a 

 field lay to the leeward of any sort of wind-break the destruc- 

 tive effects of the winds were either wholly avoided or they 

 were greatly reduced. It was found that even Grass-fields 

 and fences lying to the west and north of grain-fields had, 

 without exception, exerted an appreciable, and sometimes 

 very marked, protective influence. 



After making these observations the influence of the wood- 

 lands and wind-breaks upon the rate of evaporation to the lee- 

 ward of them was investigated with modified Piche evapo- 

 rometers. The first set of observations was made on a piece of 

 ground planted to Corn lying to the south of a grove of Black 

 Oaks having a mean height of twelve to fifteen feet. By set- 

 ting the instruments at different distances from the belt of 

 trees it was found that there was little difference in the rate of 

 evaporation at points less than 120 feet away ; but at 120 feet the 

 rate of evaporation was 17.2 per cent, greater than at twenty 

 feet. Little difference was found in evaporation at distances 

 of 280, 300 and 320 feet, but the mean evaporation at these 

 three stations was twenty-four per cent, greater than at the 

 three nearest ones. 



On May 31st another trial was made to the south of a Black 

 Oak grove eighty rods square, where the trees averaged, per- 

 haps, fifteen to twenty feet in height, and the instruments 

 showed an increase in the amount of evaporation until a dis- 

 tance of 300 feet was reached, but beyond that limit the rate 

 became constant. At 300 feet the rate of evaporation was 

 17.7 per cent, greater than at 200 feet, and 66.6 per cent, greater 

 than at twenty feet from the woods. 



Trials were also made to the leeward of a very scanty 

 hedgerow, and of a Clover-field — the hedgerow being a strip 

 of Blue Grass sixteen feet wide, in which there were scattering 



Black and Bur Oaks from six to eight feet tall, but the distri- 

 bution of these was so irregular that there were many open 

 gaps of twenty to forty feet. The Clover-field lay adjacent to 

 and west of the Potato-field and bordering the Oat-field on the 

 north, and had a width across which the air passed before reach- 

 ing the instruments of 780 feet. Here again the observations 

 showed an evident influence upon the rate of evaporation ex- 

 erted by both the Clover-field and the hedgerow — the evapora- 

 tion at 300 feet away being about 30 per cent, and 40 per cent, 

 greater than at twenty feet distant from the hedgerow and 

 from the Clover respectively. 



In view of the observations here presented it appears to me 

 that we have a case in which both the reservation of forests 

 and the planting of trees may be urged as an expedient, not 

 only for increasing the immediate crop-production, but for 

 maintaining at a smaller cost a fair degree of fertility for the 

 soil. In our state and in parts of northern Michigan we have 

 had large tracts of land, which, owing to the small natural 

 water capacity of their soils, are, when unaided, on the verge 

 of barrenness, and yet which are capable of producing remu- 

 nerative yields of potatoes and of other crops which mature 

 with a relatively small amount of water ; but I feel confident 

 that the tendency of these soils to drift and to suffer from 

 drought makes it expedient, if not necessary, to hold portions 

 of these tracts in forests. The observations here presented lead 

 me to feel that were these lands to be cultivated in narrow 

 north and south fields, leaving belts of timber, and even plant- 

 ing them when necessary, primarily to break the force of the 

 wind and to increase the relative humidity of the air which 

 passes across the fields, the total agricultural output might 

 easily exceed what would be possible were the whole surface 

 cleared and tilled, unless irrigation is resorted to. 



Then, again, nearly the whole timber district of the northern 

 half of our state has now been so thoroughly deforested by 

 man, fire and winds that the near future must witness a large 

 influx of agricultural population. Indeed, large land-owners 

 already have agents in Europe negotiating the establishment 

 of colonies within our borders, and one early colony of Finns 

 has been so planted on the shore of Lake Superior. If any- 

 thing is .to be done in the direction of forest-reservations, 

 therefore, steps to that end should be taken at once. 



Recent Publications. 



Practical Botany for Beginners. By F. O. Bower, D.Sc, 

 F.R.S. Macmillan & Co., New York. 



The natural way to study botany is to begin with the 

 common phenomena of plant-life as they present them- 

 selves to Hie senses and by observing and comparing them, 

 to get some idea of their alliances, so as to classify them 

 from their outward appearance and most conspicuous 

 characters. These external and visible relationships be- 

 tween plants are always paralleled by inner or more recon- 

 dite resemblances in cell structure, which are revealed by 

 the use of the microscope. It is the fashion in some cases 

 to begin the study of botany now with the microscope, 

 and to proceed from a study of the cell outward. To us 

 this has never appeared to be the rational method. Of 

 course, no one can know botany or any other branch of 

 biological science without careful laboratory work, and 

 when investigations of this sort are undertaken instruction is 

 needed about the necessary apparatus, the preparation of 

 material, the adjustment of the microscope, and all that. 

 This is in reality elementary work of one kind, and it is 

 eminently practical work, and when it is begun after some 

 knowledge has been acquired of systematic botany, as it is 

 generally understood, it is most fascinating as well as use- 

 ful. This little book is an attempt to guide novices in 

 their first steps in laboratory work. ' It begins with a list of 

 the apparatus required for ordinary investigations ; explains 

 the methods of preserving material, with directions for cut- 

 ting sections for mounting, etc., and then gives some prac- 

 tical exercises in the preparation of material and in the use 

 of common micro-chemical reactions. The main body of 

 the book is taken up with directions for the studying of 

 vegetative organs and reproductive organs of various 

 types. No guide available for elementary work of this 

 sort is better than Professor Bower's, and undoubtedly it will 

 find extensive use in every institution where there is a 

 botanical laboratory. 



