Vol. XII. No. 295. 



THE AGRICULTURAL NEWS. 



265 



Industrial Centres and the Supply of Tropical 

 Produce. 



Under the heading of The Trek to the Tropics, an 

 article in a recent issue of Trupical Life seeks to 

 show why England must establish agricultural colleges 

 for those colonies which lie within the torrid zone. In 

 <ireat Britain there is said to be a rural e.Kodus to the 

 towns of 10 per cent. It is obvious, then, that such 

 a movement brings a double e\il on the community 

 because it means 10 percent, more mouths to be fed 

 but 10 per cent, less producers to feed them. There 

 is, therefore, a difference of "20 per cent, in the position 

 of the supply and demand of foodstuffs. 



In continuation of this idea, the necessity in the 

 first place of an adequate suj)ply of foodstuffs hardly 

 needs pointing out. But as well as foodstuffs, there must 

 be an adequate supply of raw material for manufacturing 

 purposes in order to keep the increasing urban popula- 

 tions supplied with work, and to enable them to earn 

 the wherewithal to buy imported food. 



(Jreat Britain's tropical colonies serve, in the pro- 

 duction of raw materials like cotton and rubber, a most 

 important, economic, and truly I nqierial service, in that 

 they provide the English industrial classes with the 

 means to purchase tiour and meat imported from other 

 parts of the Empire like Canada and Australia; or, in 

 other words, the benefit circulates around the Empire. 

 The production of commodities like raw sugar and 

 cacao also serves a double purpose, in that it both 

 supplies the manufacturer with material and the com- 

 munity with food. 



From every point of view it is necessary that the 

 suppl}' from the Tropics should not merely be inaintained 

 but increased. Development will take place quickest 

 when the business and science of planting can be studied 

 on the spot under organized conditions, and when the 

 latent potentialities of the unexploited tropical posses- 

 sions are studiously kept before the eyes of desirable 



emigrants. 



^ 



Forests and Rainfall: A New Aspect. 



The inriuence of forests on rainfall is a subject 

 which is continually engaging the attention of meteor- 

 ologists and those interested in sylviculture. Scientiric 

 support of the supposition that wooded areas increase 

 or control precipitation has until recently been some- 

 what indefinite. This would appear to have been 

 due largely to the prevailing tendency to gener- 

 alize too widely. Mr. Raphael Zon, of the United 

 States Forest Service, publishes an article in 

 Science (July 18, 1913) which deals with consider- 

 ations on the subject, restricted to the effect of forests 

 on the humidity of prairie regions situated to their 

 leeward. He concludes: 'If the effect of mountainous 

 forests upon the precipitation of regions lying in the lee 

 of them is not entirely clear to us, the effect of forests 

 in wide plains of continents, especially in the path of 

 raoist winds, cannot be doubted. By increasing the 

 evaporation from the land at the expense of suriace 

 run-off, they enrich with moisture the passing air 

 currents, and in this way help to carry it in large 

 juantities into the interior of continents.' 



It v.-ould appear that the p:ecipitation of the 

 eastern half of the United States is intimately connecteij 

 with the prevailing south winds, and that land contri- 

 butes niore to precipitation than the ocean. So that in 

 spite of the fact that quantitative proof is lacking, ib 

 would appear extremely probable that the rainfall of 

 the prairie region depends upon the in'-'ience of the 

 forests of the Atlantic slopes. 



Early Conceptions Reg^arding Fungi. 



In her Presidential Address before the British 

 Mycological Society, Miss (julielma Lister, F.L.S., has 

 sketched in an able manner the work and influence of 

 past students of the mycetozoa. It may be explained 

 for the benefit of the general reader that the mycetozoa 

 constitute a v/ell-defined group of organiam.s which, as 

 the name implies, occupies an intermediate position 

 between the animal and the vegetable kingdoms. In 

 this group, a spore provided with a firm wall produces 

 on germination an amieboid swarm-cell which soon 

 acquires a flagellum or whip-like process. The swarm- 

 cells multiply by division and subsequently coalesce to 

 form a plasmodium which exhibits a rhythmic stream- 

 ing. Each swarm-cell, however, does not lose its 

 individuality. It may be noted, too, as an interestin]^ 

 and significant fact, that these swarm-cells are capable 

 of ingesting bacteria. 



To revert to the subject of Miss Lister's address, 

 it is a striking fact how strongly imagination and 

 superstition could and does govern the formation 

 of opinions. This circumstance is illustrated in the 

 following quotation from the' commencement of the 

 address: 'If the mycetozoa were observed at all by the 

 earlier Naturalists, they were considered to be Fungi, 

 and Fungi were regarded as objects of superstition and 

 mystery, rather than as living plants. 



'Writing in the second half of the 16th century, 

 the German herbalist Hieronymous Bock gave expres- 

 sion to the opinion of the times when he writes, in his 

 chapter on Fungi: 'mnshrooms are neither herbs nor 

 roots, neither flowers nor seeds, but merely the super- 

 fluous moisture of the earth and trees, of wood and 

 other rotten things." 



'Again, the Italian botanist Cesalpine 



writes in 1.5S3 : "Some plants have no seed: these are 

 the most imperfect, and spring from decaying sub- 

 stances: they have only to feed themselves and grow, 

 and are unable to produce their like: they are a sort of 

 intermediate existences between plants and inanimate 

 nature." ' 



About the beginning of the ISth century a more 

 scientific spirit began to awaken. The work of Mioheli, 

 Hallerand Linneus, but more particularly with the work 

 of Charles Persoon, the study of the fungi and especially 

 that of the Mycetozoa made great strides. Then 

 followed the studies of Fries, Berkeley and others 

 which culminated in the epoch-makirg researches of 

 Do Bary (who first observed the spores in the Mycetozoa 

 give birth to swarm- spores) and in the critical and 

 exhaustive treatment of the group by Arthur Lister 

 the father of the recently appointed President of tha 

 British Mycological Society. 



