678 



NATURE 



[August 28, 191. 



And this is the reason why a tree, when planted, 

 should not be buried deeply in the soil ; but a latitude 

 of a good many inches in the depth at which it is 

 planted has been found to make no difference, because 

 the new roots, on which the life of the tree depends, 

 form most readily at whatever depth is most suited 

 to their development, or if they form at other depths, 

 they soon make their way to the most favourable 

 level. 



The fact that roots flourish best at some partii ulai 

 level not far below the surface (the depth varying 

 in different soils) is the explanation of some results 

 which appeared to show the exact contrary. A num- 

 ber of paradise stocks were planted with their roots 

 at various depths from 6 to 24 in. below the surface, 

 and it was found that those which had been 

 buried deepest, although they were the most back- 

 ward at first, rapidly outstripped the others, and in 

 two years had made twice as much growth as these 

 had done. On lifting the trees the reason of this 

 was apparent ; in the case of those which had been 

 planted at the ordinary depth, the root-system of the 

 trees was the same as that which they had possessed 

 when planted, though more developed (Fig. 2), 

 whereas, with the buried trees, the original roots, find- 

 ing themselves at an unsuitable depth, had not 

 developed, but in their place numerous fresh roots 

 had developed from the stem of the tree itself (Fig. 3), 

 and these, finding ample food-material stored in the 

 stem, had developed strongly, and formed a vigorous 

 root-system, with the natural accompaniment of vigor- 

 ous branch growth. Such results, depending as they 

 do on the ability of the tree to send out new roots 

 from its stem, would not be obtained if a grafted tree 

 were buried in the same way, for roots do not easily 

 arise from the stem of such a tree ; indeed, when the 

 experiment was made with crab-stocks instead of 



-Apple stocks planted 6 inches below the surface, and lifted 

 two years afterwards. 



paradise-stocks, the results were unfavourable, for the 

 crab-stock does not root so easily from the stem as 

 does the paradise-stock. Thus, these experiments an' 

 the reverse of showing that an ordinary fruit-tree 

 should be planted at a great depth. 

 NO. 228/, VOL. 91] 



It will be seen that all the anomalous results which 

 have been obtained on the subject of planting are 

 easily explained by, and are the natural consequences 

 of, the fact that a tree when transplanted has to form 

 a new root-svstem before it can begin to grow again. 



and if this is but kept in view, the whole subject 

 becomes simplified, and the reason becomes evident 

 why many of the practices supposed to be essential 

 to the proper planting of a tree do not bear the test 

 of actual experiment. 



EXPLORATIONS AND FIELD-WORK OF 

 THE SMITHSONIAN INSTITUTION IN 1912. 

 T7OLLOWING the custom established in 1911, the 

 -l Smithsonian Institution has issued an illustrated 

 pamphlet dealing with the scientific expeditions con- 

 ducted under its direction, or in which its representa- 

 tives participated. The pamphlet describes the work 

 of about twenty different parties. 



The institution was represented by two small par- 

 ties in Borneo — those of Mr. H. C. Raven, who has 

 been collecting mammals and ethnological material 

 in Dutch East Borneo for the past two years, and 

 Mr. Daniel D. Streeter, of Brooklyn, N.Y., who has 

 served as a collaborator for the National Museum in 

 the collecting of mammals, in a trip through Sarawak 

 and Dutch Borneo. 



Dr. W. L. Abbott, who financed the Dutch East 

 Borneo Expedition under Mr. Raven, and has pre- 

 sented many large collections to the National Museum, 

 has been carrying on a personal investigation in Cash- 

 mere, where he has. been trapping and studying the 

 smaller mammals of that country, specimens of which 

 have been sent to the museum. 



Through the invitation of Dr. Theodore Lyman, of 

 Harvard University, the institution was enabled to 

 cooperate with the Museum of Comparative Zoology 

 in an expedition to the Altai Mountains of Siberia and 

 Mongolia. Mr. N. Hollister represented the National 



