lO 



SCIENCE 



[Vol. XX. No. 491 



To give a few instances in the Ojebway tongue: nanan, 

 5; nanominag, 5 globubar, animate objects, as turnips, 

 seeds, etc. ; nanonag, 5 boats or canoes ; naunshk, 5 breadths 

 of cloth ; and nanoshkin, 5 bags full (nflshkin meaning full) ; 

 nanosag, 5 things of wood ; nanwabik, 5 things of metal. 

 In the Zimshian language (Brit. Columbia) guel means one 

 if the object is neuter, gaul, if masculine or feminine, gou- 

 uz-giin, when the thing is long like a tree or pencil, ga'at, 

 if a flsh or animal is spoken of, gummet, if applied to a 

 canoe; the other numerals change in the same way. 



It is interesting to note that in the Ainu, the aboriginal 

 language of Japan, a distinction is made in the numeral 

 according as the object spoken of is animate or inanimate, 

 thus: shinen, one person; shinep, one thing; tun, two per- 

 sons; tup, two things. 



Sault Ste. Marie, Ontario, June 22. 



BLACK KNOT. 



Bulletin No. 40 of the New York State Experiment Sta- 

 tion at Geneva (Peter Collier, director) contains a valuable 

 summary of our present knowledge concerning this pest, 

 from which the following is abstracted : — 



The "Black Knot" is a disease of plums and cherries, 

 which causes the formation of a hard, rough, black, wart-like 

 surface on an enlarged or distorted outgrowth of the bark. 

 The following statements, furnished by Mr. P. Groom Bran- 

 dow of Athens, Green County, N.T., indicate the former ex- 

 tent and value of the plum industry in that region and its 

 total devastation by the Black Knot. 



He states that, beginning at Cedar Hill, about four miles 

 below Albany, the plum district included a belt about three 

 miles on each side of the river and extended southward about 

 thirty-six miles to Germantown. He began setting plums 

 for a commercial orchard in 1861, and at one time bad six 

 thousand trees. Two of his neighbors each had about two 

 thousand trees, and most of the farmers went into the busi- 

 ness to a greater or less extent. It was no uncommou thing 

 for a steamer to carry from one hundred to five hundred 

 barrels of plums to New York at one trip. For four days' 

 picking in one week he received $1,980. In 1884 he netted 

 §8,000 from his plums, and the next year he rooted out over 

 five thousand trees on account of the Black Knot. From 

 twenty-five hundred young trees two to three years old, 

 left at that time, he thinks he has not yet realized over 

 $250. 



It was formerly believed that Black Knot was produced 

 by some gall insect, and it is not strange that this opinion 

 prevailed on account of the gall-like character of the knots 

 and the fact that they are frequently inlested by insects. 

 Some believed it to be the work of the curculio, others 

 thought that it was not the curculio, but some other in- 

 sect or cause that produced the knots. But several years 

 ago Dr. W. G. Farlow published, in the first annual re- 

 port of the Bussey Institute, the results of his investiga- 

 tions, which proved conclusively that the Black Knot is 

 caused solely by a parasitic fungus which grows within the 

 bark, and which is now known to science by the name of 

 Plowrightia morbosa. It is recognized as growing on culti- 

 vated cherries, and also on the wild red or yellow plum, the 

 Chicasaw plum, the choke-cherry, the wild red cherry, and 

 the wild black cherry. It is commonly most destructive to 

 the plum, but also seriously attacks the cherry. 



The external appearance of the mature form of the Black 

 Knot is generally well known. It appears at this stage as a 



rough, wart-like excrescence, or distorted outgrowth, from the 

 bark of twigs and branches, and in severe cases may extend 

 along the trunk for several feet. The first outward sign of 

 the formation of a new knot is seen in a swelling of the 

 tissue within the bark either in the fall or during the grow- 

 ing season of the tree. The swelling increases till the bark 

 is ruptured, and over the surface thus exposed the fungus 

 sends out numerous threads (hypse), which produce a vel- 

 vety appearance and are of an olive-green color. Microscopic 

 examination of the velvety surface reveals multitudes of 

 newly formed and forming spores borne on these upright 

 threads. These spores (conidia) are called summer spores. 

 When full grown they drop off from the supporting threads, 

 and when carried by winds, insects, or other agencies, to 

 another host-plant, under favorable conditions they may 

 start growth and form a new centre of disease, from which 

 in time other trees may also be infested, and thus spread 

 the disease from tree to tree and neighborhood to neighbor- 

 hood. 



The best way to deal with thoroughly infested trees is to 

 cut them down and burn them at once, thus insuring the 

 destruction of the spores before they spread the disease any 

 further. Trees not badly infested may be treated by cutting 

 off affected branches some distance below the knot. This 

 operation is best performed in the fall immediately after the 

 foliage drops, because the winter spores are not formed at 

 that time and consequently there is less danger of their being 

 disseminated in the operation, and also because the work can 

 be done more thoroughly when there are no leaves to hide the 

 knot. The summer spores must also be taken care of in their 

 season. As soon as there is any indications of the formation 

 of a new knot, in the spring or during the summer," the branch 

 on which it occurs should be cut and burned. The first out- 

 break will probably be noticed about the middle of May. 



It is important to note that if a branch containing the knot 

 be cut from the tree and thrown on the ground, the spores 

 will ripen in due time just the same. Therefore the practice 

 of collecting carefully and burning every knot cannot be too 

 strongly urged. 



The bulletins of the Massachusetts Experiment Station 

 contain some experiments in the application of various sub- 

 stances for the purpose of destroying the knot. Kerosene, 

 turpentine, linseed oil, sulphate of copper, and a mixture of 

 red oxide of iron and linseed oil are mentioned among the 

 substances tried. These seem to be effective in destroying 

 warts to which they are applied to saturation, but care 

 must be used with the turpentine and kerosene or the entire 

 branch will be killed. 



LETTERS TO THE EDITOR. 



#** Correspondents are requested to he as brief as possible. The writer's name 

 is 271 all cases required as proof of good faith. 



The editor loill be glad to publish any queries consonant with the character 

 of the journal. 



On request in advance, one hundred copies of the number containing his 

 communication loill be furnished free to any correspondent. 



A Plea for the Study of Psychology. 

 The per.usal of a report, written by a member of the visiting 

 committee of one of our universities, induced me to write these 

 lines. In the course of the report, the remark is made that the 

 study of psychology is difficult, and therefore few students take 

 the study. The importance and advantage derived from studying 

 a subject are to be considered more than its difficulty. Its use- 

 fulness is determined by its educational value; and surely there is 

 no subject of study more useful and beneficial than psychology; 

 for all persons who deal with people require a knowledge of this 

 subject. 



