October 28, 1891.] 



Garden and Forest. 



515 



sion that not only could much more be done, but that it is a 

 national duty to see that much more is done in this matter of 

 increasing the number and variety of trees and flowers in our 

 towns and cities. Very little technical knowledge of the life- 

 processes of plants and the conditions necessary for their wel- 

 fare is needed to show that different species differ immensely 

 in the degrees of susceptibility to injury by means of small 

 quantities of acid fumes, such as exist in a diluted condition in 

 the smoke passing off from the tall chimneys of a busy manu- 

 facturing centre;" nevertheless, no tree will withstand the 

 worst of the conditions found in centres of industry which 

 daily give off small quantities of chlorine, hydrochloric acid or 

 sulphurous acid ; but then it must not be forgotten that 

 these worst conditions are out of all proportion to the condi- 

 tions met with in a city like London. Yet it is surprising to 

 see how gallant a struggle for life is kept up by trees like the 

 Balsam Poplar, the Black Poplar, the Alder, Sycamore, and 

 some other trees even in the worst cases referred to." Conif- 

 erous trees, the writer continues, are not nearly so well able 

 to stand these conditions, nor can the Oak, the Beech or the 

 Birch long and successfully continue the struggle, though 

 even these put up with more hardships than is popularly sup- 

 posed. The chief point he wishes to make plain is that, at 

 all events, in the smaller and more open English towns, many 

 more varieties of trees will grow than have yet been tried, and 

 that here, at any rate, "every effort ought to be made to plant 

 some of the many beautiful North American and other foreign 

 trees that can now be obtained and are known to be capable 

 of easy cultivation in such localities. Moreover, there can be 

 no doubt that much is to be done in this direction in London 

 and other large cities in spite of crowded dwellings and period- 

 ical fogs." 



Professor Ward then points out some causes for the frequent 

 failure of town trees which do not lie in the unsuitability of 

 atmospheric conditions, and his words show that municipal 

 authorities often work in England pretty much as they do in 

 America. Town trees are " fixed, when young, in a hole, prob- 

 ably filled with good soil, and this is carefully covered in, the 

 young trees suitably staked and protected, possibly the soil 

 round the base of the stem covered with a grating, and the 

 result is — failure ! True, it often takes several years to accom- 

 plish this striking result, but its inevitableness is none the less 

 assured. While the tree is young, and its root-system is revel- 

 ing in the pocket of good soil, provided with the overhead 

 grating which ensures a supply of rain-water and air, and it 

 may be of manure also, all goes well, and the head of foliage 

 above is able to make the most of what sunshine there is and 

 to manufacture the substances which supply the wood, new 

 buds, new roots, and, possibly, even flowers. But the time 

 comes when the pocket of soil is exhausted by the roots and 

 they put out spreading thread-like rootlets to explore the soil 

 around. And now comes the critical period ; these young 

 rootlets are covered with myriads of extremely fine hairs, and 

 these delicate root-hairs are the only organs which absorb the 

 water containing small quantities of substances such as salts 

 of potash, lime, nitrogen, phosphorus, etc., in solution, and 

 they are utterly incapable of performing this work of absorp- 

 tion in the absence of oxygen. Now, what are the usual con- 

 ditions of affairs in the streets of a town ? Even supposing 

 these new spreading rootlets have good soil around them, and 

 soil which is porous and deep, the rule is, that a practically 

 hermetically sealed layer of flag-stones or asphalt lies above 

 them, and their only chances of obtaining water and oxygen 

 are through the grating and soil close to the stem. No doubt, 

 the most is made of this, and the tree goes on for several years, 

 doing better than it would if the flags or asphalt came up close 

 to the stem. How often does it happen, however, that the 

 new rootlets have nothing better to spread in than old brick 

 rubbish or barren gravel ; or, far worse, a soil which is satu- 

 rated with the poison from leaking gas-pipes ? " 



Even sanitary appliances have an adverse effect upon town 

 trees, for " the neighboring sewers may be taking off, as fast 

 as they can, the water from soil round the roots, or the case 

 may be otherwise, and the stagnant water, standing too long 

 at the roots of the tree, deprives them of the oxygen neces- 

 sary for their life and lowers the temperature beyond a mini- 

 mum they could temporarily withstand. What has been 

 stated so far is enough to show that the wonder is not that 

 trees so often fail in the streets of our cities and large towns, 

 but that the interminable and dreary rows of Planes, Elms 

 and Limes that are planted ever come to anything at all." The 

 author then notes the injuries which may come to town trees 

 through the impact of vehicles, the gnawing of dogs and horses 

 and the pranks of boys, and the danger of selecting, for street- 

 planting, trees which send out long, straggling, superficial 



roots, running just under the pavement or road, because, as 

 these roots thicken with increasing age, they lift up the- flag- 

 stones or other pavement, and, becoming a source of damage 

 and danger to the street,* are likely to be injured themselves 

 by passing feet and wheels. The comparative brittleness of 

 the limbs of different trees should also be considered before 

 planting ; and, after planting, proper methods of pruning or 

 otherwise treating a tree which is in delicate health or has 

 suffered external injury should be determined. 



Although, says Professor Ward, for one reason or another, 

 " the Oak, Ash, Birch, Beech and some others of our forest- 

 trees are unsuitable for town-planting, this is no sufficient 

 reason for flooding London with Planes, and Planes only, as if 

 no such trees as Robinias, Laburnums and American Oaks, 

 Ashes, Walnuts, Maples, etc., existed. Moreover, there is 

 every reason to predict success for trees as yet undreamt of 

 as town ornaments. Let those in authority try some of the 

 hardy Magnolias — say M. acuminata, probably one of the best 

 town trees — and extend their experiments to such as the 

 Robinia, the Laburnum, the Tulip-tree, the Mulberry, Fig, 

 Catalpa, and the beautiful Maiden-hair tree of Japan. The list 

 might also include the Almond, Black Walnut, and various 

 species of Sophora, Kolreuteria, Cercis, Gymnocladus, Acer, 

 Rhus, Tilia, Liquidambar, etc. Some judgment would have 

 to be exercised in the matter, of course, but probably all of the 

 trees here mentioned would succeed if properly planted. . . . 

 As regards Poplars, Ashes, Alders, Pavias, Limes, Gleditsia, 

 Horse-chestnuts, Thorns, etc. ... I will simply remark that 

 these and many more can be placed in the list of trees and 

 shrubs fit to be planted in large towns and cities ; some, of 

 course, are more fit for our cleaner and less smoky country 

 towns, but many would resist the evil influences of a London at- 

 mosphere if properly planted and cared for." We have omitted 

 the lists of shrubs, climbers and smaller plants which Professor 

 Ward also gives, but may cite his mention of the fact that there 

 was, a year or two ago, a fine specimen of Ptelea trifoliata 

 flourishing in the heart of the city of London on the premises 

 of the Tinies newspaper. "Surely," he says, "after this we 

 need not despair, and it behooves all those who are concerned 

 in furnishing towns with those ' lungs ' so necessary for pros- 

 perity in the true sense, to bestir themselves and look through 

 the lists of likely plants." It may interest Professor Ward to 

 know that some of the American trees he recommends flour- 

 ish well in the streets of American towns. 



Notes. 



Messrs. Pitcher & Manda announce an exhibition of Chry- 

 santhemums, Palms, Ferns and Orchids at the United States 

 Nurseries, Short Hills, New Jersey, to continue during this week. 



During the famine which has recently afflicted the Volga 

 regions, in Russia, the peasants have found their chief source 

 of subsistence in bread made from a Chenopodium, the com- 

 mon way-side weed which we will call Goosefoot. 



Professor N. S. Shaler, of Harvard University, whose excel- 

 lent book on the "Aspects of the Earth" we reviewed a year 

 or two ago, is about to publish another, called " Nature and Man 

 in America," which will explain in a popular form the influence 

 that environment exerts upon man. 



A correspondent deplores the popular taste which makes it 

 possible for a boy made of Roses, Immortelles and Carnations, 

 and trousers made of Roses and Pinks, to be among the con- 

 structions spoken of as " beautiful and numerous floral trib- 

 utes " at the opening of a business house lately. 



The study of plants first existed as a branch of medical 

 knowledge. When Hippocrates, "the father of medicine," 

 compiled a list of all medicinal plants known to him only 300 

 were named. In the time of Theophrastus, the famous pupil 

 of Aristotle, some 500 species could be described, and in the 

 first Christian century, when Dioscorides wrote, 100 more 

 were known. 



Among the new books which should interest lovers of nature 

 we notice "Sharp Eyes," a collection of studies of insect, bird 

 and flower-life, by W. Hamilton Gibson; " Japonica," by Sir 

 Edwin Arnold, and "The Warwickshire Avon," by Mr. T. 

 Ouiller-Couch, illustrated by Mr. Alfred Parsons. Of the 

 charms of the last-named two we have already spoken during 

 their serial publication in Scribner's Magazine and Harper's 

 Monthly. 



In Insect Life, for October, it is stated by way of example of 

 what may be done to mitigate insect attacks, that in the states 

 of North Dakota and Minnesota there has been during the 



