564 SCIENCE PROGRESS 



whilst the south-western part belongs to the Sub-atlantis 

 region (north German plain west of Sarmatia). 



Burgess {Soil Science, Sept. 1922) describes a new type of 

 press for directly obtaining the true soil solution. Com- 

 parisons of the composition of solutions obtained by this means 

 with the ordinary i : 5 pure water extract show a fairly close 

 correspondence as regards Calcium, Magnesium, and Nitrate 

 ions, but the water extract yielded i-y times as much sulphate 

 and 3-5 times as much Potassium ions. The discrepancy 

 with respect to the Phosphate ion was even greater, being 

 about 30 times more than in the real soil solution. 



Larsen, in Ecology for October, gives some interesting data 

 obtained by the U.S. Forest Service respecting the efifect of 

 forests on meteorological data from three stations, one in the 

 dense forest, a second in a partially cleared area (one-third 

 forest), and a third in an open clearing. The range and 

 extremes of temperature diminished with the increase of 

 cover, as also the average daily evaporation and soil tempera- 

 ture. The relative humidity increased with the increase of 

 cover. 



PLANT PHYSIOLOGY. By R. C. Knight, D.Sc, Imperial CoUege of 

 Science and Technology (Plant Physiology Committee). 



Physiological Action of Fungicides. — Shortly after the intro- 

 duction of Bordeaux mixture as a fungicide, it was observed 

 that its application resulted in changes in the sprayed plants 

 which could not be attributed merely to the fungicidal action. 

 Much isolated work on this question was reported from Euro- 

 pean sources from about 1890 onwards, and it is only more 

 recently that the matter has been seriously investigated. It 

 is perhaps to be expected that the distribution over the plant 

 of compounds of copper will not be without effect upon the 

 plant itself, apart from the toxic action on fungi, and of course 

 extreme cases of " Bordeaux injury " are of fairly common 

 occurrence. Grubb {Jonrn. Pomology, 1921, 2), in the course 

 of tests of fungicides on apples, made observations on spray 

 injury and devotes a section of his paper to its consideration. 

 Bordeaux injury is manifested by the early fall of the leaf, 

 generally within a few weeks of spraying, and also by the 

 russeting of the fruit. This injury appears to be decreased 

 almost to zero, without loss of fungicidal action, by the use 

 of excess of lime. Apart, however, from the extreme cases 

 of injury due to the toxicity of the strength of spray applied, 

 there are other physiological effects of the spray which may 

 have a very important influence on the constitution of the 

 plant and its crop. Grubb observes that in general the appli- 

 cation of a spray increases the size of the individual fruits 



