70 



SCIENCE. 



[N. S. Vol. XIV. No. 341. 



into dense balls, epiphyte ferns are in abun- 

 dance, fallen trunks are covered with moss, and 

 the path through the jungle chokes up so 

 quickly that it has to be cut open often. The 

 jungle is said to contain 1,500 species of trees. 

 The Malays are very keen in perceiving dis- 

 tinctions, and recognize two species of oaks 

 there which the botanists have not yet dis- 

 criminated. On the heights the aspect becomes 

 more European, Viola, Ranunculus, Primula, 

 Lonicera, Lobelia, Oxalis, etc., appear, and 

 Wallace explained this by supposing these 

 northern forms were pushed south by a glacial 

 climate and on the retreat of the ice they 

 themselves retreated to the mountains. 



Edward S. Burgess, 



Secretary. 



THE ACADEMY OF SCIENCE OF ST. LOUIS. 



At the meeting of the Academy of Science 

 of St. Louis, on the evening of June 3, 22 per- 

 sons present, the following subjects were pre- 

 sented : 



A paper by Dr. Gellert Alleman, on ' The 

 Action of Alcohol on Certain Isomeric Dlazo 

 Compounds,' and one by Dr. G. Hambach, en- 

 titled 'A Eevision of the Blastoidese,' were 

 presented by title. 



Mr. Wm. H. Roever, of Washington Univer- 

 sity, read a paper on ' The Effect of the Earth's 

 Eotation upon Falling Bodies,' in which he 

 showed that a body falling from a great height 

 has a southward deviation in the northern hem- 

 isphere and a northward deviation in the south- 

 ern hemisphere. The deviation is given by the 

 formula — 



A = 7i 



i(^+iy 



^ sin cos (j) 



l + -j Kcos'cl, 



(^+-^) 



Ksinf cos <p 



in which h is the height through which the body 

 falls, B the radius of the earth (assumed spher- 

 ical), (j) the latitude of the place of observation, 

 K the numerical fraction zh and A the devia- 

 tion. If h and B are given in feet, A is in 

 feet. 



For h = 578 feet and <p = 45°, A = .00133 inch. 



Mr. G. Pauls presented a number of speci- 

 mens collected at Eureka, Mo. He exhibited 

 a large number of galls on hickoiy, maple and 

 oak leaves, commenting on the remarkable va- 

 riety of the forms of galls made by the minute 

 insects. He had bred a good many of these in- 

 sects, and found that in successive years a good 

 many different forms came from these galls. 

 William Trelease, 

 Becording Secretary. 



CURRENT NOTES ON PHYSIOGRAPHY. 



NEW MAP OF THE MISSISSIPPI. 



The ' Preliminary Map of the Mississippi 

 Eiver from the mouth of the Ohio Eiver to the 'f^t^^ 

 head of the Passes,' published by the Mississippi :-"'' ' 

 Eiver Commission (1881-1885, 32 sheets, one - 

 inch to a mile), is now to be supplemented by 

 a new edition, of which 13 sheets are issued, X 

 bearing in red overprint the changes wrought 

 by the river in about fifteen years. These 

 new sheets are without question the most in- 

 structive exhibition of river work, quantita-- 

 tively determined, yet published in this coun- 

 try ; for a river of the first magnitude they 

 have no rival in the world. They deserve to 

 be widely known not only among engineers for 

 whom they were primarily constructed, but 

 among geographers and teachers to whom they 

 convey much information. The general be- 

 havior of the meandering river may be in- 

 ferred from the maps of the earlier edition, 

 from which it appears that the meander system 

 slowly moves down the valley, because the 

 thread of fastest current, thrown toward the 

 outer side of every curve, is therefore delivered 

 to the down-valley side of every tangent or 

 ' crossing ' (so called because river boats must 

 there cross the river obliquely in following the 

 channel of greatest depth) ; and that the mean- 

 der belt included between tangents drawn out- 

 side of the curves slowly widens as the curves 

 increase in radius and arc until it here and 

 there suddenly collapses when a curve is cut 

 off. It may be noted in passing that it is for 

 this reason that the abandoned curves — the 

 ox-bow lakes — are frequently of larger radius 

 than the average of the existing curves. The 



