SCIENCE. 



[N. S. Vol. II. No. 29. 



NOTES ON AGRICVLTUEE ( V.) 

 NATIVE PLUMS AND RUSSIAN CHERRIES. 



Mr. Hedrich, in Bulletin ISTo. 123 of the 

 Michigan Experiment Station, states that 

 our native plums are coming into promi- 

 nence. They are three weeks earlier than 

 the European sorts, and of the 150 varieties 

 the De Soto, Wild Goose and Miner are the 

 most promising. They are not particular 

 as to soil and desirable 'because of their 

 immunity from diseases and insects.' 



The introduction of cherries from Russia 

 dates from 1882. They are recommended 

 for localities too cold for ordinary cherries. 

 The fruit is reddish black in color, late in 

 maturing and with ' a peculiar astringent 

 flavor which is often very pleasant.' 



PINEAPPLE CULTURE. 



Bulletin No. 27 from the Forida Experi- 

 ment Station gives, first of all, a full-page 

 plate of a pineapple field in full fruit. Dr. 

 Washburn, the experimenter, has raised the 

 peculiar fruit crop for nine years, and is 

 convinced that it is profitable and that 

 ' pines ' can be grown over a large portion 

 of Florida. The plants need to be set 

 eighteen inches apart each way and abun- 

 dantly supplied with rich food. 



THE FLOW OF MAPLE SAP. 



It is natural to expect that nearly eveiy 

 subject connected with the production of 

 food supplies will be considered by the Ex- 

 periment Stations. The one by Mr. Woods 

 of the N.- H. Station is upon the flow of sap 

 in maple trees. It is found that the flow of 

 sap is dependent largely upon the depth of 

 the hole, or ' tap,' and the idea that nearly 

 all the sap comes from the outer wood is 

 erroneous, and that sugar makers may 

 profitably tap their trees to a depth of four 

 inches. It was also shown that there is 

 very little gain by tapping a tree in two 

 places; one deep and small hole upon the 

 south side of the tree is sufficient. 



damping off. 



Professor Atkinson, in Bulletin No. 9i of 

 the Cornell Station, reports at length upon 

 a study of microscopic fungi that work upon 

 seedling plants in greenhouses and destroy 

 them by what is commonly known as 

 * damping ofli".' This fatal result is occa- 

 sioned by great moisture content of the soil, 

 high temperatures, close rooms and insuffi- 

 cient light — all of which favor the growth 

 of the low forms of fungi, causing the de- 

 struction of the stems of the seedling. The 

 conditions above given should be as far as 

 possible eliminated. As the moulds, etc., 

 enter the plants fi'om the soil it is evident 

 that the latter should be as free as may 

 be of the germs. Diseased plants need 

 to be thrown away and, in serious cases, 

 the soil likewise. The soil may be steril- 

 ized by steam heating before the seeds are 

 sown. Those who would have healthy 

 greenhouse plants must be wise as mycolo- 

 gists and as loving as mothers. 



Byron D. Halsted. 



SCIENTIFIC NOTES AND NEWS. 

 THE CONGRESS OF PHYSIOLOGISTS. 



As we have already stated, the third Inter- 

 national Congress of Physiologists will be held 

 at Bern, September 9th to 13th, 1895. Prof. 

 Kronecker, director of the phj'siological 

 laboratoiy of the University, has kindlj' ex- 

 pressed his readiness to afibrd to members 

 of the Congress all facilities for demonsti'a- 

 tion and experiment, as well as for the ex- 

 hibition of scientific apparatus. It is es- 

 pecially wished to have a full exhibition of 

 apparatus, which may be contributed either 

 by physiologists or by instrument makers re- 

 commended by members of the Congress. 

 Titles of communications from America may 

 be sent to Professor Frederic S. Lee, Secre- 

 tarj-, American Physiological Society, Colum- 

 bia College, New York City. Professor Bow- 

 ditch has signified his intention to be pres- 



