8 



Garden and Forest. 



[January 2, iS 



sent out by the French raisers. This year, however, really 

 good varieties seem the rule rather than the exception, and 

 the majority prove very valuable, in that they are early bloom- 

 ers, an important item with those who grow their Chrysan- 

 themums in the open air. Among the most distinct and 

 meritorious of the year are Benoit Rozain, rosy pink, of good 

 size and texture and perfectly formed ; Condor, pure white, 

 with broad, pendulous Hat pe:,talSu; Cythfere, rosy violet, of 

 immense size ; Gustave Nadaud, with long, creamy petals, as 

 roimd as seine cord, and a tiower nearly globular ; Harman 

 Payne, bright rose ; Magicienne, a large spathed orange- 

 brown ; Pierre Destombes, probably the finest of the set, with 

 very long, needle-shaped florets of silvery dove color, the 

 tiower measuring six inches in diameter ; Sabine and Nelson, 

 two unusually large anemone flowered kinds, the first sulphur 

 yellow, the other ashes of roses. All these varieties are dis- 

 tinct in color, of wonderful form, and are equal to any varie- 

 ties shown in this country, and yet we frankly confess that 

 those of the Philadelphia prize set sent out by Craig last 

 year are the very finest twelve varieties ever introduced at one 

 time. 



Richmond, Indiana. ^- ^- -tiUl. 



Principles of Physiological Botany as applied to 

 Horticulture and Forestry. 



I. — Introductory : Reduction of a Plant to its Lowest Terms, 

 Cells. — The Living Matter in a Plant. — Division of Labor. 



"PHYSIOLOGICAL botany endeavors to investigate every rea- 

 ^ sonable question regarding the structure and the life of 

 plants. It depends for the appliances which it uses in research 

 chiefly upon Physics and Chemistry, and therefore its 

 progress has been largely governed by the progress 

 made in those departments of investigation. Hence it 

 has been only within a very few years that improvements in 

 the construction of certain instruments, notably the com- 

 pound microscope, have rendered it possible for the physi- 

 ologist to examine satisfactorily some of the more obscure 

 processes of growth and of nutrition. Improved methods of 

 research in chemistry, especially what is known as micro- 

 chemistry, have lately enabled physiologists to attack some 

 questions which were formerly considered to be beyond the 

 reach of investigation ; consequently, many ditficulties have 

 been cleared up in recent years. Although far too many 

 questions have not even yet been answered satisfactorily, the 

 additions to our knowledge of the phenomena presented by 

 plants have been important and are worthy of careful consid- 

 eration. 



It seems proper that these recent discoveries in regard to 

 the structure and life of plants should find some place in a 

 journal devoted to the advancement of two important inter- 

 ests which are based largely on physiological botany, namely, 

 forestry and horticulture. But, at the same time, it is clear 

 that accounts of these discoveries can be given in a journal of 

 this character only under certain difficulties, inasmuch as they 

 must be presented in connection with a general view of the 

 subject, and in language as free as possible from technicali- 

 ties. Moreover, many of the broad, general statements can- 

 not, from the nature of the case, be very strictly qualified, 

 since reference to the numerous minor exceptions must be 

 omitted. The latter are to be looked for in comprehensive 

 treatises.* 



The present series of familiar papers will deal with flower- 

 ing plants — that is, with plants which produce true flowers 

 and seeds, and the examples will be drawn as much as possi- 

 ble from those which possess special interest from the point 

 of view of forestry and horticulture. These plants will be 

 examined with reference to the manner in which they procure 

 their food and perform their work. It is, therefore, necessary 

 to obtain, at the outset, a general idea of the structure of 

 plants ; this can be most conveniently done by examining the 

 plant as if it were, wh'at indeed it is, a machine. 



The plant as a machine. — When we have any piece of ma- 

 chinery to investigate, our first aim is to ascertain what its 

 essential parts are — that is, by reducing it to its lowest terms, 

 we try to find out what parts could be dispensed with, if we 

 wanted to make a simpler machine to do the same kind of 

 work. Now, in all cases, we find that we can reduce plants to 

 what must appear, at first, very simple terms, namely, cells. 

 These cells are bodies of exceedingly minute size, extremely 



*The following works will be found useful for reference : 

 Gray's Botanical Text-book, Sixth Edition. 



Vol. I. — Structural Botany. 



Vol. II. — Physiological Botany. 

 Vine's Physiology of Plants. 

 Sachs' Lectures on The Physiology of Plants. 



diverse in form and general character, but all possessing cer- 

 tain features in common. These microscopic bodies, or 

 cells, are variously united together to make up the structure 

 of the different organs of the plant; hence we must examine 

 the features which these constituents of the plant have in 

 common before we can examine to advantage the plant itself. 



If we make a thin slice through any active, living part of a 

 plant, as, for instance, the tip of the root or the very tip of the 

 stem, we see, under the compound microscope, that it is 

 composed of what look like irregular cavities in a confused 

 mass, and this is the view which the earliest observers held 

 in regard to them. But we now know that these cavities are 

 the interiors of minute bodies which are more or less firmly 

 connected together, and which, from their union, give the 

 whole mass a honeycombed appearance. Each of these 

 bodies or cells coheres, by means of its wall, with the cells 

 next to it. In the youngest parts the walls are thin and deli- 

 cate, but as the part grows older the walls undergo great 

 changes in thickness, hardness, color and so on, but great as 

 these changes are, they are not so marked as that which goes 

 on at the same time in the interior of the cell. 



Each young living cell is filled more or less completely with 

 living matter, technically termed protoplasm. This living 

 matter in the cells is the only living thing in the whole plant; 

 upon its health, activity and life depend the health, activity and 

 the life of the plant. As long as the living matter in a cell is 

 in a state of health and activity, the different kinds of work 

 can go on. But it often happens, for instance in the cells of 

 a seed which is fully ripe, that the living matter may become 

 for a time inactive, but still ready to resume its activity under 

 favorable conditions. Or, as is more frequently the case in 

 our woody plants, the living matter may, as it builds up new 

 cells, leave the seat of its former activities, and abandon the 

 thick-walled cavity for a new home in the living and younger 

 parts. When' the living matter thus removes bodily, so to 

 speak, from the older cavities, the shells, or cases, or old cell- 

 walls, which once held it, become dead. 



This is precisely what happens in the formation of woody 

 parts; the cavities no longer contain living matter; their 

 walls are simply the empty cases or shells of what once were 

 the walls of living cells, now dead. Hence, when we speak 

 of a piece of heart- wood exhibiting, under the microscope, the 

 shapes of the cells, we mean merely that we have here the 

 now hardened walls of what were once active, living cells. 



It is difficult to realize that the only living parts in the stout 

 trunk of a tree are the cells which are just under the bark, and 

 the cells which are situated here and there in the bark itself. 

 The wood, which plays such an important part as a mechani- 

 cal support, is lifeless ; it is the record of what once had life ; 

 it was built up by the living matter which now has passed on 

 to further work of construction. 



Nor is it less difficult to realize the significance of a fact 

 which has been discovered within the last few years, namely, 

 that an intimate union exists between the living contents of 

 neighboring cells. It has been shown that the living matter 

 in one active cell is connected with living matter in contigu- 

 ous cells by exceedingly delicate threads of the same sub- 

 stance. 



It is only by the use of recent {"mprovements in appliances 

 for invesdgation that these threads of living matter can be 

 shown to exist, and hence formerly it was taught that there 

 was no continuity between the living matter in one cell and 

 that in those next to it. The discovery that such a vital con- 

 nection does exist has led to a generalization which is proba- 

 bly sound, that all the living matter throughout a plant is in 

 reality continuous. 



There are inany plants of minute size in which the living 

 matter can be studied easily. These microscopic plants in- 

 habit fresh water and possess the power of taking from it all 

 they need for nutrifion and growth. They simply consist of 

 single cells, and .yet they are able to perform practically all 

 the kinds of work done by plants of such complicated struct- 

 ure as our forest trees and garden shrubs. 



But in these exceedingly simple plants, where the dif- 

 ferent kinds of work ai'e performed by a single cell, there 

 is no clear division of labor ; at least we cannot see by what 

 part of the cell the absorption of food-materials takes place, 

 or by what parts respiration is carried on. When, however, 

 we examine any one of the common plants about which this 

 series is to treat, there is more or less distinct separation of 

 the kinds of work, and the division of labor requires different 

 organs. These organs, such as roots, stems and leaves, all 

 co-operate as completely as did the indistinguishable parts in 

 the plants composed of a single cell ; all the living cells in 

 all the organs co-operate ; each assists the others and is 



