184 PATHOLOGY [Bot. Absts., Vol. VI 



found to be most practicable. The following diseases are discussed: early blight, late blight, 

 Fusarium wilt, Sclerotium wilt, late blight rot, storage rots, corky scab, black scurf or russet 

 scab, tuber moth, borers, cut worms, and mites. — /. M. Westgate. 



1264. Chaine, J. L'attaque des vegetaux par les Termites. [Termite attacks on plants.] 

 Rev. Gen. Sci. Pures et Appliquees 31: 250-255, 281-285. 1920.— Termes lucifugus, a white 

 ant of tropical origin, late in the eighteenth century invaded Rochelle, Rochefort and other 

 places in western France, gradually spreading from there over a wide area and causing consider- 

 able damage, not only to buildings, furniture, and other structures of dead wood, but to liv- 

 ing trees, shrubs and even herbaceous plants. A proposed method of control is outlined 

 which consists in irrigation of the affected trees by one or another of three solutions, trenches 

 holding 200 to 300 liters being used for this purpose. The essential ingredients of these solu- 

 tions are mercuric bichloride, potassium ferrocyanide and potassium ferricyanide respectively, 

 and these are used at approximately 3 per cent concentration. Irrigation with these solutions 

 was repeated two or three times at intervals of two days, and then the trenches were refilled 

 with soil. There were three such irrigations per annum, in the winter, spring and fall. Com- 

 parison at the end of the first year showed that the treated trees looked slightly better than 

 the rest. At the end of the second year, however, the trees treated with the mercuric bichlor- 

 ide and the potassium ferrocyanide solutions no longer gave any external evidence of ter- 

 mites, while those treated with the ferricyanide merely showed great improvement. Exten- 

 sion of this method to the protection of potatoes, oats, cabbage, etc., seemed to be entirely 

 successful up to 1914, and to have no ill effects upon the animals fed upon the materials thus 

 protected. — G. J. Peirce. 



1265 Conneb, S. D., and E. N. Febgtjs. Borax in fertilizers. Purdue Univ. Agric. 

 Exp. Sta. 239. 15 p., fig. 1-4. 1920.— See Bot. Absts. 6, Entry 1381. 



1266. Duddleston, B. H. The modified rag doll and germinator box. Purdue Univ. Agric. 

 Exp. Sta. Bull. 236. 12 p., 7 fig. 1920— See Bot. Absts. 6, Entry 477. 



1267. Gboom, Pebcy. Brown oak. Quart. Jour. Forest. 14: 103-109. 1920.— When 

 certain individual British oak trees, not differing in form in any recognizable way from the 

 normal, are felled, it is discovered that their heart-wood is wholly or partially represented by 

 a much more valuable type of wood known as "brown oak" or "red oak." This wood is firm 

 in texture and deeper or richer in color than the normal wood. Sometimes uniformly colored, 

 at other times it is traversed by bands or studded with patches of lighter and darker wood, 

 which may in places be nearly black. This latter variegated type is the so-called "tortoise- 

 shell" variety. The United Kingdom is the sole known geographical source of this product. 

 In the trunk, the brown wood most frequently occurs at the base, extends upwards and down- 

 wards into the root for a variable distance, often tapering in such a manner that its ends appar- 

 ently conicide with the inmost heart-wood. In the trunk, the brown wood, when traced 

 upward, sometimes becomes confined to one side; and when the trunk divides into two or more 

 leaders, the brown wood may ascend one but be lacking from the others. It may occur in 

 upper parts of the tree but be partially or entirely lacking in any lower part of the trunk. In 

 the trunk, the brown wood often stops at a large knot, and in such cases, the large limb con- 

 nected with the knot is devoid of brown oak. Of two oak trees growing side by side, one may 

 be normal and the other have the brown wood. The brown wood is often encountered in the 

 form of burr-wood (burl). This brown wood is firm and hard. — Under the miscroscope, mature 

 "brown oak" structurally agrees with ordinary oak hardwood. It differs from this only by 

 the presence of considerable qxiantities of solid brown substance in the cavities (especially in 

 the parenchyma) and the firmness with which it holds tannin. Careful microscopic investi- 

 gations and cultural experiments lead to the conclusion that the coloring of the wood is due to 

 a fungus whose identity is as yet unknown. The hyphae possess little power of attacking the 

 walls, but feed nearly exclusively on substances in cells and especially of the parenchyma. At 

 the expense of its food material, the fungus manufactures coloring materials that darken the 

 wood. — C. R. Tillotson. 



