December 9, 19 15] 



NATURE 



405 



or of attending" to it. A small change in excitation 

 disturbs the pre-existing cortical system so as to bring 

 about the reaction time more slowly than does a large 

 one, not because of the resistance to its conduction, 

 but because of the inertia of the pre-existing central 

 system. Physiologists and psychologists will find the 

 article interesting and controversial. 



In the Philippine Journal of Science, vol. x., No. 5, 



for September, 1915, Mr. E. D. Merrill continues his 

 [descriptions of new or noteworthy plants from the 



Philippines. This instalment, which is No. xii. of the 

 [ series, includes seven genera credited for the first time 



to the Archipelago, viz., Avena, Polytoca, Angelesia, 

 [Glyptopetalum, Ochrocarpus, Asystasia, and Poly- 



trema. Sixty-two new species are described belonging 

 [to various families, and in all eighty species are added 

 [to the Philippine flora. The Avena is, no doubt, an 

 [introduced plant. 



The cultivation of sisal hemp and its preparation 



forms the subject of an article in the Bulletin of the 



[mperial Institute, vol. xiii., No. 3. From Mexico, the 



)me of the plant, it has been widely distributed, and 



|is now being successfully "grown in British East Africa 



ind in the Bahamas has long been introduced. The 



tide deals especially with the history of the introduc- 



of the plant into various countries and the pre- 



iration of the fibre for market, where its chief use 



in the making of twine. It is pointed out that for 



"a successful enterprise large areas must be planted, 



[xxially if a factory is to be erected. Details with 



^ures are given of British machinery for the prepara- 



ion of the fibre. 



The annual report of the Department of Agriculture, 

 I ganda, for the year ending March 31, 1915, is a record 

 of useful and steady progress. An interesting account 

 of coffee cultivation is given, from which it is seen 

 that the cofTee-leaf disease (Hemileia vastatrix) is on 

 the wane, and does not appear to be seriously affecting 

 tlie cofTee plantations in the country. A chart is given 

 sliowing the fluctuations in the amount of the disease 

 compared with rainfall and humidity on the Govern- 

 mcnt plantation, Kampala, but the outstanding feature 

 )f the chart is that the disease reaches its maximum 

 during the months July to September. Other fungus 

 parasites are dealt with in the report of the Botanist, 

 but there does not appear to be any serious disease 

 affecting the economic products in Uganda. 



The ninety-third Report of the Commissioners of 

 Woods, Forests, and Land Revenues, dated June 29, 

 is mainly concerned with the financial state for the 

 year of the Crown properties under their charge. 

 These are multifarious in kind, including, in addition 

 to land let for buildings, foreshores, mineral rights, 

 etc., 346,935 acres, of which 69,103 acres are under 

 the growth of timber. The main centre of active 

 forestry operations is the Dean Forest and High- 

 meadow Woods in Gloucestershire, which are about 

 to be used as a forestry demonstration area. The old 

 school for the training of woodmen at Parkend has 

 been extended to include more men under instruction ; 

 and a new School for Forest Students is now being 

 erected near Speech House. The wood distillation 

 NO. 2406, VOL. 96] 



works, which were opened in October, 1913, have 

 proved successful. Large quantities of charcoal and 

 fuel-wood from the various Crown forests were 

 dispsltched to the trenches in Flanders. Increased 

 quantities of pit-wood have been sold from 

 Dean Forest and Tintern Woods. The Crown holds 

 in England 73,375 acres of agricultural estates, con- 

 sisting mainly of farms varying from 50 to 1000 acres 

 in extent ; but 9,374 acres are now let for small hold- 

 ings and allotments. The greater part of the latter 

 have been created in the past nine years, during which 

 period eighty-seven new cottages and seventy new sets 

 of farm buildings were erected, whilst existing cot- 

 tages and homesteads were altered and improved. 



According to the Bulletin of Economic and Social 

 Intelligence issued by the International Institute of 

 Agriculture, the co-operative movement is very suc- 

 cessful in Finland, where 10 per cent, of the whole 

 population are members of such societies ; this pro- 

 portion, in fact, is only surpassed by Denmark, where 

 the corresponding figure is 25 per cent. An unusual 

 organisation of the kind is that established for the 

 working of peat moors. The use of peat litter in 

 retaining the most valuable constituents of manure is 

 generally recognised, and since Finland is very rich 

 in peat deposits, their working in the interests of agri- 

 culture has developed greatly. The co-operative 

 society buys a moor, or acquires the right of extract- 

 ing peat, constructs the necessary drying sheds, and 

 then sells the peat to its members. Some of these 

 societies are very large, owning plant to the value of 

 40ooi., and exporting their peat abroad. 



A THIRD article on the ec6nomic resources of the 

 German colonies, dealing this time with those in West 

 Africa, is published in the new number of the 

 Bulletin of the Imperial Institute. The Cameroons, the 

 chief peak of which rises to 13,000 feet, export rubber, 

 palm kernels, cacao, and palm oil especially, and also 

 to a smaller extent gum arable, kola, and shea nuts. 

 Some attention has been devoted to the cultivation of 

 tobacco with considerable prospects of success. Stock- 

 breeding, as in other German colonies, has been well 

 developed, despite the difficulties caused by tsetse fly. 

 Much of the territory is unexplored, but so far no 

 minerals of particular economic importance are 

 known. It may be added that so far as the flora is 

 concerned, the region is remarkably interesting. 

 Togoland exports oil palm products, maize, rubber, 

 and cacao, and cotton, copra, ground nuts, and kajxjk 

 are among the minor articles of export. A good deal 

 of attention has also been paid to forestry, with pro- 

 mising results. Iron ores occur abundantly, and good 

 limestone is also found, but lack of transport facilities 

 has prevented the establishment of any definite iron- 

 ore industry. 



Thi-; recently received second number of the fifth 

 volume of the Journal of Agricultural Research, pub- 

 lished by the Department of Agriculture in Washing- 

 ton, contains tw'o interesting phytopathological papers 

 by Mr. I. E. Melhus. In the first of these it is 

 pointed out that the possession of perennial mycelium, 

 hibernating in the tissues of their respective host- 

 plants, is a characteristic feature of many species of 



