104 



Garden and Forest. 



[February 27, li 



Many attempts have lieen made to import this plant in quan- 

 tity, but every consignment, no matter how it may he 

 packed, is ahiiost worthless on its arrival, and very few 

 plants survive the close and impure atmosphere to which 

 they are subjected on their passage to this coimtry. This 

 Orchid will, in all probability, therefore, remain a rare plant 

 for years to come. It grows very freely at the coolest end of 

 the Cattleya-house in a shady situation, and should occupy a 

 basket or pan suspended as near the light as possible, in a 

 mixtm-e of clear sphagnum and rough, fibrous peat, with am- 

 ple drainage. In full sunlight its thin, fieshy stems will soon 

 become weak and perish. 

 Summit, N.J. A. Dvinnock. 



Some Choice Narcissus.— The beautiful little N. Cyclamhieas 

 has ]iro\'ed to be of easy culture. Collected bulbs flowering 

 with us for the second season, show a marked improvement, 

 both in size and quantity of bloom. Let us hope that this little 

 gem, after having been lost to cultivation for more than 250 

 years, has come at last to stay. N. triandrus', from Portugal, 

 is now opening in abundance its pretty, pale, pendent flowers. 

 This is often considered hard to keep, but thrives well here 

 under the treatment given to others of its class in a soil 

 two parts loam to one of peat. The varieties of N. Bulboco- 

 diiim give a display for several months, commencing with var. 

 monopJiylhis, which is white and of the characteristic " Hoop 

 Petticoat" form. Var. citriniis comes next, with pale yel- 

 low flowers, which are just now at their best. N. Bulbocoduini 

 is the last in order of flowering, and comes a month later. We 

 have also a form of TV. Biilbocodium from Portugal which is 

 quite distinct, no two bulbs producing flowers alike, but differ- 

 ing principally in the cut-off appearance of the corona. To 

 the above may be added TV. serotinus and TV jiincafolius, 

 making an interesting collection for those who have small 

 space at their disposal. All the above-named do well in live- 

 inch pots at a temperature of 50° to 55°. 



Passaic, N. J. E. O. Or pet. 



Principles of Physiological Botany as Applied to 



Horticulture and Forestry. 



IX. Changes of Organic Matter Within the Plant (Continued). 



A^fE have already seen that the first product of assimilation 

 ** proper, that process by which the plant converts 

 inorganic materials under certain conditions into organic mat- 

 ter, is probably some form of sugar. In the last paper it was 

 pointed out that this primary substance bears peculiar relations 

 to starch, the first visible solid product of assimilation. We 

 are now to examine the physiological relations of the group to 

 which sugar belongs and see in what way this is utilized by the 

 plant as food. 



There are three chief groups of sugars found in plants. 

 They differ from each other in the proportions of hydrogen 

 and oxygen which they contain, and they possess somewhat 

 different physical properties. They are known as (i) the 

 directly fermentable, (2) the indirectly fermentable, and (3) the 

 non-fermentable ; that is, they sustain difterent relations to 

 certain microscopic organisms by which the process of fer- 

 mentation is carried on. 



The sugars of the first group may be represented by grape 

 sugar, sometimes known as glucose, which occurs to the 

 amount of five to thirty per cent, in certain ripe fruits. It is 

 crystallizable, Init lacks the high degree of sweetness which 

 we associate with the type of the second class, namely, cane 

 sugar. This latter is the sugar of the sugar cane, and of the 

 sugar beet, and of sorghum, but it is generally associated with 

 a certain amount of other forms of sugar, and by the very 

 process of extraction a portion of the cane sugar maybe more 

 or less completely transformed into the less desirable kinds. 

 The third group is represented by a substance which may be 

 procured from certain Acacias, etc. Sugars of the last group 

 are wholly incapaljle of ordinary saccharine fermentation ; 

 those of the second ferment only after they have become 

 acted on by soine agent which partially modifies their original 

 character, while those of the first are very easily, and, as one 

 may say, directly fermentalile under almost any conditions. 

 But all of these, like members of the starch series, are capable 

 of undergoing oxidation, giving up thereby a portion of their 

 enei;gy of position, which reappears as energy of motion. The 

 ultimate products of the complete conversion of these sub- 

 stances are carbon dioxide and water, the inorganic materials 

 from which they were first brought together by the agency of 

 the plant under the influence of the sunlight. 



It should be borne in mind that the few sugars here 



mentioneil are only representatives of classes, and that these 

 classes by no means exhaust the list. Moreover, it should be 

 remembered that the sugars occur in diflerent amounts in 

 difl'erent plants, and, as is the case with many other substances, 

 in different amounts in different parts, and, in the same part, at 

 different periods of its development. 



The second great group of substances containing carbon, 

 hydrogen and oxygen, but no nitrogen, is that of the vegetable 

 fats or oils. These are of very complex composition, and do 

 not need to be here commented on from a chemical point of 

 view, further than to take note of the fact that they contain 

 relatively less oxygen tlian the suljstances before mentioned. 



The fats or oils sustain peculiar relations to the living mat- 

 ter of the plant, especially while the latter is in a state of 

 rest or of suspended activity, as in the case of ripe seeds. It is 

 interesting to observe that the seeds of liy far the greater 

 proportion of species contain their food stored up, not in the 

 form of starch, but of oil of some sort. In many cases the oil 

 is capable of drying when exposed to the air, as is the case 

 with thtit of flax seed (linseed oil), while in others it does not 

 thicken rapidly, if at all. Oils of the first sort are extensively 

 used in ordinary painting. The so-called volatile oils, such as 

 tlie fragrant oils of the different members of the Mint order, 

 are closely related to the turpentines, and are not to be con- 

 founded with members of the group of true fats. 



It is a curious fact that in some, if not most, cases thus far 

 observed, the fats or oils of seeds are in part transformed into 

 other carbo-hydrates, such as starch, before they are utilized 

 by the seedling. Thus the seed-leaves of the Castor-bean 

 have been shown to take from the general supply a certain 

 portion of the oil as such, and during conveyal to other' parts, 

 or somewhat later, to transform at least some of it into starch, 

 which can be detected in the form of cliaracteristic granules. 



The third group of these substances free from nitrogen 

 comprises the vegetable acids, such as Tartaric (in grapes), 

 Malic (in apples). Citric (in lemons), and the like. Most of 

 these are found in difterent proportions, and are never free 

 from admixture, so that we may find even more than two of 

 these in the same fruit, some of them occurring, perhaps, in 

 mere traces only. One of the vegetaljle acids most frequently 

 found is Oxalic, which is generally combined with calcium to 

 form crystals of calcium oxalate, abundant in plants. In other 

 cases it imites with potassium. In most instances there is also 

 more or less of this acid remaining uncombined. It is diffi- 

 cult to form a clear conception of the direct use of these acids 

 to the plant, except so far as they play an important part in the 

 protection of the plant or some of its organs, as, for instance, 

 its fruits, from unwelcome guests. This aspect of the subject 

 will be examined at a later period, when we come to glance at 

 the methods of dissemination of seeds. 



Among the less important substances, which may be alluded 

 to in connection with those now examined, are various astrin- 

 gent matters; for instance, members of the Tannin group. 

 These occur in almost every part of the plant at some period 

 of its growth. Widely different views ha\'e been entertained 

 as to the origin and the probable use by the plant of these 

 substances, some investigators holding that the members of. 

 the tannin series are waste matters, while others believe that 

 they are reserve materials. In some cases they seem to have 

 a very plain function in defending the plant from its enemies, 

 but this, which is only a specialized office, will be incidentally 

 referred to later. Associated with the tannin-hke bodies are 

 the curious principles which occur in certain barks, such as 

 aesculin, in the bark of the Horse-chestnut, etc. 



From the extremely long list of other subtances free from 

 nitrogen, only the following can now be noticed in passing: (i) 

 the ethereal oils, compounds of carbon and hydrogen, and (2) 

 the resinous matters, which are much the same as the last, 

 but are combined with more or less oxygen. Both of these 

 classes of substances are obscure in their origin in the vegeta- 

 ble laboratory, and in most cases it is difficult to hazard any 

 reasonable conjecture as to their work in the plant. Probably 

 they always have or have had some office of attraction (as is 

 clear in the instance of the perfumes of certain flowers), or of 

 defence, as is seen in innumerable cases. But we may possi- 

 bly get a hint as to their office and occurrence when we re- 

 member that during the life of a given species its surroundings 

 must have changed in many ways, and that possibly attractions 

 and modes of defence required at an earlier stage are now no 

 longer useful to the plants under existing conditions. And it 

 is well known that a great many peculiarities of all sorts ])er- 

 sist long after the conditions to which they were adapted, or 

 which may haA^e called them forth, have passed away. 



In concluding this sketch of the substances free from nitro- 

 gen, we are now able to say that they fall naturally into two 



