July 10, isin 



HARDWOOD RECORD 



19 



nature stored there for the use of the tree while it was growing. 

 This consists of starch and other materials. It is iu the cells of the 

 sapwood when the tree is cut, and it remains there after the lumber 

 is sawed, and it constitutes the bait that tempts the fungus to 

 enter. This stored food is not found in the heartwood in suiBeient 

 quantity to attract the fungus threads to enter, and that is the rea- 

 son why the stain is confined to sajiwood. Where food is not to be 

 found, this fungus does not go. 



Herein lies the explanation, why it is called sapstain instead of 

 woodstain. It operates in sapwood only. It dies of starvation as 

 soon as it enters heartwood; but there are other species of fungus 

 which work their way into heartwood and cause it to decav. They 



DAMAGED PACKING BOXES 

 Sapstained lumber fsapwood) may become so dark that the stenciling 

 Is scarcely read.ible, but heartwood remains light. 



generally act much more slowly than the species which specialize 

 on sapwood and produce the discoloration and stain which cause so 

 much injury in lumber yards. 



The Dispersal of Spoees 



The most discouraging feature of the fight against sapstain is 

 that it seems to be everywhere. Lay down a freshly-sawed board 

 of sapwood, and it is attacked so quickly and with such vigor that 

 every square inch of the exposed surface is soon stained. It does 

 not seem to make much difference where the board is, provided 

 "the weather is not too cold or too dry. The fungus is there, ready 

 for the attack. 



The sapstain plague is spread by spores. The spore of fungus 

 corresponds to the seed of a flowering plant. The seeds of many 

 plants are wonderfully successful in traveling from place to place 

 and getting themselves planted where chances to grow are good. 

 They roll by gravity, as walnuts; float iu water, as mangrove; fly in 

 air, as maple; hang to the fur or wool of animals, as cockleburs and 

 beggarlice. But the spores of fungus surpass all seeds of the higher 

 plants in moving from locality to locality. In the first place, they 

 are more numerous and more of them start on the journey. A puff- 

 ball the size of a marble can scatter more spores in one day than the 

 largest walnut tree can scatter seeds in a century, and the spores go 

 faster and farther. In fact, spores have such adequate facilities 

 for getting from place to place that they seldom fail to arrive 

 everywhere promptly. Some are as light as the finest dust and 

 float in the air for hours and drift far from the starting place. The 

 ' ' smoke " of a puffball and the ' ' smut " On a cornstalk afford ex- 

 amples of spores which may be seen floating in clouds composed of 

 millions of individuals, and each individual capable of starting a 

 new generation. 



Some spores which do their traveling by water are equipped with 

 from one to a dozen tails, resembling those of eels, but the spores 

 are so diminutive that it is almost impossible to imagine anything 

 smaller. When one of these spores starts upon its journey through 

 the water, it lashes its tails as if it were a living thing, and quickly 

 arrives at its destination. Spores of that kind belong to algae. 

 Then there is the spore of the equisetum or scouring rush. This 



spore perambulates somewhat after the fashion of a grasshopper. 

 It has appendages resembling long, slender legs. When not on a 

 journey the appendages are coiled like springs round its bean- 

 shaped body. When the order comes to "forward-march," one leg 

 kicks out, then the other, first one and then the other, and the spore 

 lurches along at an interesting rate. The kicking propensities of a 

 mule are half-hearted compared with the spore of equisetum. If 

 the spore were as large as the mule, and strong according, it could 

 kick itself from New Yoi'k to San Francisco in two hours. Some 

 spores have wings, and apparently they can use them as successfully 

 in sailing through air as alga spores use their tails in swimming 

 through water. Most spores of fungus, however, can float along in 

 air because of extremely small size and light weight. They drift 

 with air currents, totally invisible to human eyes and in numbers 

 almost surpassing the powers of figures to express. 



They account for the presence of sapstain whetever climatic con- 

 ditions are favorable. The spores fall on every exposed surface; 

 and where moisture, warmth and food are found, germinate and 

 grow quickly. Freshly sawed wood is a fertile soil for this nefari- 

 ous crop. Dampness and the food conditions are exactly right. 



How Wood Is Discolored 



When lumber is infected by fungus the fact may be disclosed by 

 change in the wood's color, but that does not always happen. In 

 some instances the threads of fungus may contain the color Ihat 

 becomes visible and which is ordinarily assumed to belong to the 

 wood itself. That is, perhaps, usually the case. The apparent 

 color o'f the wood is sometimes, as seems probable, thfe result of an 

 optical effect. The brown threads of fungus are visible through the 

 yellowish fibers of the wood and the eye interprets the result as 

 a bluish tinge, though the real wood substance may have no such 

 tinge. 



The different species of fungus that produce sapstain vary con- 

 siderably in color, independently of all optical illusions. One 

 such fungus has been used in the manufacture of green dye. So 



- V , 1 



. , ■ ;< 



£=> ^ MAXV/EI.L 



s;iIOWER OF SAI'ST.i^IN SPORES OX LUMBER PILE 

 This shows what actually takes place, though the falling spores are too 

 small to be visible to the naked eye. 



much coloring matter is contained in this fungus that it imparts a 

 green tinge to the wood that contains it. 



It is thought probable that the real wood substance is not dis- 

 colored, but that the stain is contained within the cells. The blue 

 stain in the cell may be compared to blue ink in a bottle. The ink 

 causes the glass to appear blue, yet the glass itself is not colored. 

 The glass in this example corresponds to the walls of the wood 

 cell. However, a discussion of this fine distinction approaches 

 jjrettv close to the line separating the known from the unknown. 



The analogy is not perfect; for, though ink may be poured from 

 the bottle and iu that way the color may be removed, the fungus 

 that has worked its way into wood cells cannot be" removed, for 

 which reason the stain is permanent. It may be covered with paint 



