ii8 



Garden and Forest. 



[Number 211. 



autumn, and associates well with the early-blooming section 

 of Chrysanthemums best represented by the variety Madame 

 Desgranges, the Daisy forming the outer ring to the bed, the 

 centre filled up with the Chrysanthemum. Both grow freely 

 in ordinary soil. ,. _ 



Kew. *'• t.. 



Correspondence. 

 Constitutional Health of Plants. 



To the Editor of Garden and Forest : 



Sir, — Observing the growths of the various plants we notice 

 that some of them are unthrifty, and when closely inspected 

 we find them infested by microscopic parasites. Other plants 

 we see preyed upon by insects, which, like the fungi, eat the 

 substance of the plant. We may also notice other plants, 

 growing under apparently similar conditions, but free from 

 fungus or insect, and apparently healthy in the midst of pesti- 

 lential influences. 



Fungi and insects evidently choose their food, and where 

 there is a choice of adaptable foods they often show a decided 

 preference. The potato-beetle feeds upon the Egg-plant, the 

 Tomato-plant and the Potato-plant, but, where all of these are 

 equally accessible, the Potato-plant will be chosen the first. 

 The rose-bug feeds upon all sorts of Grape-vines, but it pre- 

 fers those containing the blood of Vitis riparia, and where it finds 

 some of these vines in the vineyard it will feed chiefly upon 

 them, nor eat of other vines until these are devoured. 

 Hence viticulturists advise the interspersing of a few Riparia- 

 vines in the vineyard to attract this insect from other varieties. 



Just as higher plants refuse to grow in some soils and thrive 

 in others, fungi show their preferences for one or another 

 host-plant. The black rot of the Grape infests almost all va- 

 rieties of the vine, yet among them the omnipresent spores of 

 this parasite manifest this elective affinity in a remarkable way. 

 For example, in ordinary seasons favorable to thrift of the vine 

 and unfavorable to activity of this fungus, the Ives are com- 

 paratively exempt from attacks of this so-called disease. Yet 

 vineyards of the Ives are sometimes ravaged by the black rot, 

 proving that this variety of Vitis Labrusca is not specifically 

 resistant to the fungus. But in the behavior of the fungus 

 with relation to this vine we have interesting proof of the ac- 

 tion of those subtle preferences, already alluded to as elective 

 affinities. In 1873, when the grape rot first became severely 

 epidemic in southern New Jersey, I noticed in one of my vine- 

 yards a few Ives Grape-vines free from the disease, while sur- 

 rounding Concords were all rotting. Soon afterward, in a re- 

 port from the state of Illinois, I was informed that " the Ives 

 grape does not rot." I then procured Ives vines, and in a 

 small vineyard of five hundred Concords, set twelve feet apart 

 along the rows, I planted Ives vines intermediately with the 

 Concords, purposing, if the latter proved unsafisfactory, finally 

 to extirpate them. At the same time I planted another vine- 

 yard of two thousand Ives vines. All of these vines, Ives and 

 Concord, came in fruit together. Grape rot was epidemic, and 

 destructive to the Concord. In the vineyard of mixed Ives and 

 Concord the latter all rotted, while the Ives grapes did not rot 

 at all. The vines of both sorts interlaced on the trellis, and 

 here were clusters of Concord totally ruined by rot, while 

 among them, and almost touching them, were clusters of Ives 

 completely healthy. In this mixed vineyard this phenomenon 

 of diseased Concords and healthy Ives has been yearly manifest. 



On the other hand, in the vineyard where two thousand Ives 

 are planted by themselves, there is yearly more orless of grape 

 rot, appearing sporadically, but never so badly as on Concord- 

 vines. When this Ives vineyard was planted, a few vines failed 

 to grow ; these were replaced by Concords. When the latter 

 came in fruit the rot took full possession of them, while the 

 Ives growing nearest to the rottingConcords were the healthiest 

 of any of the Ives-vines in the vineyard. It looked almost as 

 if the germs of the rot fungus were endowed with the power 

 of motion, and had abandoned the Ives vines to feed upon the 

 Concords. 



Certainly each minute organism has its own peculiar way of 

 propagating its species, and in getting a living makes choice of 

 congenial foods. Now, since this choice of food is directed by 

 some peculiar quality in the juices or tissue of the plant which 

 are attractive to these devourers, or else repellant to them, it 

 may be possible by an enlightened use of special fertilization, 

 or by medication, to influence or modify the qualities of culti- 

 vated plants, so as to render them unattractive to these ag- 

 gressors. Why is it impossible for science to discover proph- 

 ylactics for the diseases of plants as it has done for contagious 

 diseases of animals ? Such prophylacdcs might be adminis- 



tered through the natural channels of absorption with plant- 

 food. Or if the subtle germ or virus productive of disease can 

 be transmitted from plant to plant by inoculation, as in the 

 case of Peach yellow, perhaps the antidotes (when we discover 

 them) may be also thus applied. 



Experience shows that plants stimulated into vigorous 

 growth by special fertilizers are often peculiarly exempt from 

 the attacks of insects and of fungi. Evidently, there is that in 

 the juices of such plants which does not please their taste. I 

 planted some Potatoes on poor soil, where they made but 

 feeble growth. Near this plat was one planted with similar 

 Potatoes, fully fertilized, and stimulated by nitrogenous ma- 

 nures. The weak plants on the poor soil were attacked by 

 the beetle and devoured before the strong plants were touched. 

 This is ordinarily explained by saying that the fertilized plant 

 grows faster than the bug can eat it ; but, in fact, the beefles 

 did not visit these plants. When they had consumed the plat 

 of weaker plants they sought other fields of similarly starved 

 Potatoes and ate these in preference. 



These two Potato-plats also showed a remarkable contrast 

 in resistance to the Potato-blight, which, when it became epi- 

 demic, attacked the weaker ones first and totally killed them. 

 The stronger plants were blighted later, but the leaves only 

 were harmed. The stalks were unaffected, and, after the foli- 

 age perished under the fungus, they put forth a new growth, 

 which endured until frost, maturing a crop of tubers. Evi- 

 dently, fertilization promotes the health of the Potato-plant, 

 and enables it to resist some diseases. There is reason to hope 

 that when we shall have learned how to feed the plant with all 

 of the requisites to health, we may secure more complete 

 exemption from contagious disease. ^ ^,^ „ 



Vineland, N.J. A. IV. PearsOtl. 



The Tan Bark Oak. 



To the Editor of Garden and Forest : 



Sir, — Among Californian Oaks, and there are many, none are 

 more beautiful than Ouercus densiflora. It is an evergreen, 

 and forms in appearance a connecting link between the Oak 

 and the Chestnut. The leaves, elliptical in outline, light green 

 above and fuzzy beneath, are shed in summer. In July it 

 blossoms, and the very foetid odor of the flowers is the one 

 disagreeable trait of this fine tree. It bears a true acorn, ob- 

 long in shape, set in a shallow cup, which, on account of long, 

 slender light green scales, seems moss-covered. The bark is 

 thick and rough, exceedingly rich in tannin. The wood 

 is straight-grained and tough, excellent for fuel, and will, 

 in all probability, be found valuable to the wood-worker. It 

 ranges from Monterey County north to Mount Shasta, in the 

 Coast-range of California, being pretty closely confined to the 

 Redwood belt. At Mount Shasta it grows as a bush five to 

 eight feet high, covering considerable areas. 



It is in the Redwood region that it attains its greatest perfec- 

 tion, and it is everywhere a tree of the mountains. On the 

 open ridges the Tan Bark Oak is a great spreading tree, fre- 

 quently three feet in diameter and fifty in height. 



The dense shade of the Redwood forest forces every tree to 

 grow up for light and air, and in such situations this Oak 

 grows as erect as a Pine, almost bare of branches for two- 

 thirds its height, seldom over two feet in diameter and fre- 

 quently sixty to eighty in height. 



It is on the eastern or interior edge of the Redwood belt that 

 it is most abundant, forming the principal growth on the ridges, 

 and preponderating on the upper slopes. Its commercial 

 value is great, and the demand so much that it is now being 

 hauled by wagon twenty to thirty miles over rough mountain- 

 roads to reach the railroads or sea-coast, and large areas are 

 stripped annually. Nearly all of these mountain-roads follow 

 the ridges, enabling the bark-peelers to secure the bark readily 

 along not only the main ridges, but the laterals. 



The workers, with their families, move out into the woods 

 for the summer. A Redwood is cut, and the lumber split out 

 for the cabins, sheds, stables, and even the board chimneys. 

 A few lengths of one of these big trees will split into enough 

 lumber to build quite a settlement. The Oaks are cut close to 

 the ground, and the bark scored off into four-foot lengths. It 

 is then peeled and thrown down to dry. When dry it rolls. 

 The hill-sides are very steep, and to get this bark to the wood- 

 roads hand-sleds are used. In some places where wood-roads 

 would be expensive, pack-mules have been used. 



Nothing but the bark is used, and after the peelers have 

 gone through a maze of trunk and branch covers the ground, 

 to rot or be burned by the next forest-fire. Of course, the 

 wood is used for fuel in some few places accessible to ship- 

 ping-points, but it may be said safely that not one-tenth is so 



