SEPTEMBER 2, 1896.] 



Garden and Forest. 



353 



aesthetic havealready been alluded to. The library, herbarium, 

 museums and laboratories are the sources whence exact infor- 

 mation regarding the name, structure, habits, life processes 

 and products of plants are derived, and they are the more 

 useful as they are the more complete and thoroughly equipped. 

 It is practically impossible for any one library to have all the 

 literature of botany and related sciences; any one herbarium 

 to possess an authentic and complete representation of all 

 species of plants ; or any one museum to be thoroughly illus- 

 trative; absolute perfection along these lines cannot be 

 obtained, but the more closely it is approximated the better 

 the results. The research work of the scientific department 

 should be organized along all lines of botanical inquiry, includ- 

 ing taxonomy, morphology, anatomy, physiology and palaeon- 

 tology, and the laboratories should afford ample opportunities 

 and equipment for their successful prosecution. 



The arrangement of the areas devoted to systematic plant- 

 ing and the proper labeling of the species grown are impor- 

 tant duties of the scientific department. The sequence of 

 classes, orders and families is usually made to follow some 

 " botanical system." It is highly desirable that this should be 

 a system which indicates the natural relations of the families, 

 as understood at the time the garden is laid out, and be elastic 

 enough to admit of subsequent modification, as more exact 

 information relative to these relationships is obtained. The 

 weight of present opinion is overwhelmingly in favor of an 

 arrangement from the more simple to the more complex, and 

 this will apply not only to the systematic plantation, but to the 

 systematic museum and the herbarium. 



The scientific possibilities of a botanical garden are the 

 greater it an organic or cooperative relationship exists between 

 it and a university, thus affording ready facilities for informa- 

 tion on other sciences. 



The Philanthropic Element. — A botanical garden oper- 

 ates as a valuable philanthropic agency, both directly and 

 indirectly. Its direct influence lies through its affording an 

 orderly arranged institution for the instruction, information 

 and recreation of the people, and it is the more efficient for 

 these purposes than a park, as it is the more completely 

 developed and liberally maintained. Its indirect, but equally 

 important, philanthropic operation is through the discovery 

 and dissemination of tacts concerning plants and their prod- 

 ucts, obtained through the studies ot the scientific staff and by 

 others using the scientific equipment. 



Number and Distribution of Botanical Gardens. — There 

 are somewhat over 200 institutions denominated botanical gar- 

 dens, but only a few of them meet the requirements of the 

 foregoing sketch. Some are essentially pleasure parks, with 

 the plants more or less labeled ; most ot them pay some atten- 

 tion to taxonomy and morphology; many to economic botany, 

 while a small number are admirably equipped in all branches 

 ot the science. 



I have drawn freely on Professor Penhallow's first annual 

 report of the Montreal Botanical Garden, published in 1886, for 

 the following approximate statement of the number in different 

 countries : 



Algeria, 1 ; Australia, 3 ; Austro-Hungarv, 13; Belgium, 5 ; 

 Brazil, 2 ; Canada, 1 ; Canary Islands, 1 ; Cape of Good Hope, 

 3 ; Ceylon, 1 ; Chili, 1 ; China, 1 ; Cochin China. I ; Denmark, 

 2 ; Ecuador, 1 ; Egypt 1 ; France, 22 ; Germany, 36 ; Great 

 Britain and Ireland, 12 ; Greece, 1 ; Guatemala, 1 ; Guiana, 1 ; 

 Holland, 4; India, 7; Italy, 23; Japan, 1 ; Java, I ; Malta, I ; 

 Mauritius, 1 ; Natal, 1 ; New Zealand, I ; Norway, I ; Peru, 1 ; 

 Philippine Islands, 1 ; Portugal, 3; Reunion, 1 ; Roumania, 2; 

 Russia, 16 ; Servia, 1 ; Siberia, 1 ; Spain, 2 ; Straits Settlements, 

 1 ; Sweden, 6 ; Switzerland, 4 ; Tasmania, 1 ; United States, 

 10 ; West Indies, 6. 



The Sand Dunes of Northern Indiana and their 

 Flora. — I. 



THE higher sand dunes by the south-eastern shore of 

 Lake Michigan begin about twenty miles from 

 Chicago and extend to Michigan City, forming a belt from 

 one to three miles wide, 'which becomes narrower as it 

 sweeps around the shores to the north-east. A spur runs 

 westward from Millers, Indiana, and comes nearly up to 

 the boundary of Illinois, making a narrow belt of sand 

 hills, bordering the north side of the marshy tract through 

 which the Calumet River sluggishly winds. Between this 

 belt and the lake is a region of low sand ridges and 

 sloughs, approximately parallel with the shore and the 

 Calumet, which here drains an area once under the waters 



of the lake. These ridges rise but a few feet above the 

 lake-level, so that the region is swampy and has a flora 

 differing from that of the higher dunes. The drier areas 

 and narrow ridges form the Pine-ba'rrens proper, in which 

 the Gray Pine prevails. 



The dune region is a confused mass of hills and hollows, 

 the deeper depressions being shallow ponds. The features 

 of this region have been shaped by two prevailing wind 

 currents from the north-west and the south-west. The 

 former predominates, and is most active in autumn and 

 winter. Coming across the lake it takes up the sand washed 

 ashore by the waves and drives it in upon the land, so that 

 a severe storm from this quarter on the lake is accompa- 

 nied by a corresponding storm of sand among the dunes, 

 and the sharp particles are piled in drifts as fantastic in 

 shape as those made by snow. This wind makes the prin- 

 cipal ridges generally parallel with the shore. But winds 

 from the west and south-west act upon these moving ridges 

 and throw up others with an axis nearly north and south. 



The shifting sands as they are blown along bury lower 

 ridges and fill up hollows lying in their pathway. Their 

 vegetation shares the same fate. Some have been so long 

 undisturbed that Pine-trees thirty inches in diameter are 

 found growing on the ridges. Those from six inches to a 

 foot in diameter are seen on dunes quite near the shore. 

 As some of the highest dunes rise from eight}- to a hundred 

 feet above the level of the lake, they are capable of cover- 

 ing trees of considerable height which may be growing in 

 the hollows. This shifting of the sand in large masses is 

 practically confined to a strip scarcely more than half a 

 mile wide along the shore, for the greater part of the hills 

 have been secured by the growth of vegetation. This cap- 

 turing of the dunes must have begun upon their southern 

 or eastern margin, or the old lake beach, and has worked 

 its way toward the lake till it now holds the greater part of 

 the area once covered by the waters ot Lake Michigan 

 when the land at its southern end stood at a lower level, 

 and the discharge was south-westward to the Mississippi. 

 The work went on till in places it has come close to the 

 shore. But in the region of the higher dunes in this belt of 

 shifting sands, though a dune may be captured and held 

 for a long time, there is no permanent security. Where 

 the winds have full sweep near the shore and fresh ma- 

 terial is supplied by the sand constantly washed up by the 

 waves, there is a tendency ever to beat back the vegeta- 

 tion. There is a ceaseless struggle between the opposing 

 forces, sometimes one, sometimes the other, prevailing. It 

 is plain to be seen that if the trees were removed from the 

 dunes back from the shore they would in time be blown 

 farther inland and encroach upon the arable ground. A 

 belt of these sand hills, with their covering of vegetation, 

 must be preserved as a screen, or artificial barriers will 

 have to be provided. As they are of little account for 

 tillage they are likely to remain, and however much of the 

 sand may be taken away for filling and grading in swampy 

 areas, the supply is so great and is so continuously re- 

 newed that it is practically inexhaustible. The greatest 

 danger comes from fires, but they are guarded 

 more than formerly, even with the multiplicand: 

 roads as a constant menace. Fortunately, also, the Oak- 

 trees and many of the shrubs have roots or subterranean 

 shoots which the fires do not reach, and they quickly renew 

 themselves if their exposed parts have been destroyed. 



The changes to which the dunes have been subjected at 

 some period of their history help to explain one of the 

 peculiar features of their lima and its mixed character. 

 Plants are repeatedly found mingled with those naturally 

 looked for in such localities that contravene our ideas of 

 their adaptations to certain habitats currently accorded 

 them in books, and generally in harmony with expe- 

 rience. Judged by such standards they are out of place. 

 Doubtless some of these plants have a greater flexi- 

 bility in adapting themselves to changed conditions 

 than is usually granted them, but the principal reason 

 for their presence in such places must be the supply of 



