September i, 1893.] 



SCIENCE. 



117 



university, in summing up his criticism on experimental 

 psychology, said that the new results of that science, for 

 example, Weber's law, were not strictly true; and their 

 true and valuable results had been set forth centuries be- 

 fore in rational psychology. In the other congress, 

 shortly after, I heard the representative of another great 

 university say that a single study in experimental jasy- 

 chology, carefully worked out, was of more value than all 

 the works on rational psychology which had ever been 

 written. A friendly rivalry betv»'een the advocates of 

 different methods is probably stimulating and favorable 

 to the development of science; but the depreciating of all 

 methods except one's own, and the rejection or neglect of 

 results obtained by other methods, is certainly detri- 

 mental to the specialist himself, and it lessens the relia- 

 bility of his work. A conference between all those inter- 

 ested in j)sychology wovild have been very desirable. 



There were some surprises at these congresses for 

 which the programs could not prepare us. At the 

 Congress on Rational Psychology, over which the vener- 

 able ex-President McCosh presided, some irrational speak- 

 ers persisted in making themselves prominent when the 

 subjects were open for discussion. On the other hand, 

 at the Conference on Aerial Navigation, where some peo- 

 ple went expecting to see the "cranks," there was nothing 

 but plain statements of observations made, exj^eriments 

 tried, results achieved and theorems proved. At no other 

 congress, perhaps, was there such a pressure of really 

 valuable and original matter. The three days set apart 

 for the conference, with doubt as to whether so miich 

 time would be needed for the discussion of such an em- 

 bryonic art, proved to be quite insufficient; and even a 

 fourth day did not give time for the reading of several 

 valuable memoii's offered by practical and scientific men 

 who are devoting much of their time to arts aerial without 

 hope of any immediate financial return. 



The Congress on Woman Suffrage was notable for the 

 large number of men present who seemed to enthusi- 

 astically support the claims of their sisters. The Con- 

 gress on Jurisprudence and Law Reform, where the most 

 serious debates might have been expected, was character- 

 ized by the amusing stories and reminiscences of vener- 

 able judges. 



The Congress on Social Settlements was a very earnest 

 conference between ardent young college graduates, who 

 constitute most of these settlements, and philanthropists 

 and socialists. 



The number of eminent visitors from abroa.d who have 

 participated in most of these congresses has been suffi- 

 cient to make the term "International" no misnomer. So 

 many valuable papers have been read at these meetings, 

 and the average excellence has been so high, that it is 

 very desirable that the proceedings of all the congresses, 

 including the discussion of papers, should be published 

 in uniform style, fully indexed, and offered for sale at a 

 j)rice to secure a large circulation. An effort is to be 

 made to have such an edition published and widely dis- 

 tributed by our government. The whole work would be 

 a kind of thesaurus of practical knovvledge. The theorists 

 and visionaries have contributed their part to each sub- 

 ject, but generally it has been only a subordinate jsart; 

 and the proceedings as a whole have been characterized 

 by great practical wisdom. 



The World's Congresses have been a kind of university 

 for which the fair has served as museums, laboratories 

 and recreation grounds. The congresses, although they 

 have the mottoes, "Not things, but men," "Not matter, 

 but mind," are officially designated as "auxiliary" to the 

 exposition; I am inclined, however, to consider the expo- 

 sition as auxiliary to the congresses. 



A NEW FACTOR IN FRUIT GROWING. 



BY B. T. GAILOWAY, WASHINGTON, D. C. 



DuEiNG the past three years the Division of Vegetable 

 Pathology in the U. S. Department of Agriculture has 

 been engaged in the study of tvsdg or fire blight of the 

 pear and apple. In the course of these investigations, 

 which were for the most part carried on by Mr. M. B. 

 Waite, an assistant in the Division, an attempt was made 

 to obtain some definite information in regard to the rela- 

 tion of insects to the disease in question. As a result of 

 this work it was shown that the organism causing blight 

 was disseminated by insects during their visits to the 

 blossoms. The blossoms, it was found, were readily in- 

 fected by the pear blight germs brought to them by in- 

 sects, the result being the death of the flower and fre- 

 quently the twig or branch supporting the latter. This 

 discovery raised the question of the necessity of insect 

 visits to the flowers of pears and other fruits affected by 

 blight. It was thought that if by some jDractical means 

 insects could be excluded from the flowers without inter- 

 fering with the fruitfulness of the trees, one form of 

 blight at least might be j^revented. 



In order to obtain some information in regard to the 

 effect on fruitfulness of excluding insects a series of ex- 

 periments were made at Brockport, New York, in the 

 spring of 1891. The results of these trials were some- 

 what startling, as it seemed to indicate a fact hitherto 

 overlooked by scientific and practical men, viz., that 

 many of our well-known varieties of jsears will not set 

 fruit unless their flowers receive pollen from other vari- 

 eties. In other woods, the visits of insects, by means of 

 which cross-fertilization is effected, is necessary to insure 

 proper setting of the fruit. 



To obtain further information on this subject more ex- 

 tended experiments were made on this subject in 1892 

 and 1893. This work was carried on in Virginia, New 

 York, and New Jersey, the results in every case confirming 

 those obtained in 1891. The facts obtained by these in- 

 vestigations seemed sufficient to warrant the important 

 conclusion that most of our common varieties of pears 

 and apples are unable to fertilize themselves. This law 

 can hardly be called new, for Knight, Darwin and others 

 have touched the same point in a broader and more gen- 

 eral way. Strange to say, however, no one, up to the 

 jDresent time, seems to have applied the conceptions of 

 Darwin and others on this subject to some of our common 

 fruits, although it has long been recognized that orchards 

 of pears, ajjples, plums, etc., fail to bear fruit regularly, 

 even under the most favorable conditions. 



In the light of our present knowledge it is known that 

 unfruitfulness, in many cases, is due to the fact that large 

 blocks of single varieties have been ^jlanted. In such 

 cases there is not sufficient foreign pollen to effect fer- 

 tilization, consequently the trees bloom profusely but no 

 fruit sets. The new factor, therefore, which confronts 

 the grower of pears and aj^ples is to select his varieties 

 and jDlant them in such a way as to insure cross-fertiliza- 

 tion. Of course, in doing this it will be necessary to ob- 

 serve a number of important points, the details of which 

 need not be given here. Suffice it to say that the time of 

 flowering of the various varieties must be kept in mind in 

 selecting those designed for pollinating. Then again, the 

 question of the potency of the pollen with respect to the 

 variety it is intended to grow must of necessity be con- 

 sidered, and, finally, it will be important to know what 

 proportion of pollinating trees to trees it is desired to 

 fruit should be planted. 



