May 21, 1909] 



SCIENCE 



823 



Looking over the lists one notes species of 

 Podocarpus (Taxaceae) and Callitris (Pina- 

 ceae). Phoenix and Hyphaene (Palmaceae), 

 many genera and species of Anacardiaceae, 

 Celastraceae, Ehenaceae, Flacouriiaceae, Legu- 

 minosae, Moraceae, Proteaceae and Buhi- 

 aceae. Very few of the genera are identical 

 with ours, although one may find such names 

 as Bhu^ (with over 20 species), Ilex, Bio- 

 ^pyros. Euphorbia, Vaccinium, Bicinus, Aca- 

 cia, Mimosa, Cassia, Ficus, Olea, Bhamnus, 

 Cephalanthus, Xanthoxylum, Salix, Celtis. 

 Aside from these the genera are quite unfa- 

 miliar to the American dendrologist. 



The other papers include such topics as the 

 breeding of maize, ramie cultivation, plants 

 poisonous to stock, and the cultivation of 

 alfalfa (lucerne). The latter is very fuU, 

 and includes over eighty pages, with a num- 

 ber of illustrations. 



A NEW BOTANICAL JOURNAL 



Early in the year (February 27) the first 

 number of a new journal appeared under the 

 name Mycologia. On the title-page it is said 

 to be " in continuation of the Journal of 

 Mycology founded by W. K. Kellerman, J. B. 

 Ellis and B. M. Everhart in 1885." It is 

 to be " published bimonthly for the New 

 York Botanical Garden." About the mid- 

 dle of April the second (March) number 

 appeared, and we are thus able to judge as to 

 what the new journal is to be like. The first 

 number contains a good colored plate of 

 agarics and pore fungi, and one black-and^ 

 white plate. The text includes twenty-six 

 pages, and the articles are entitled " Illustra- 

 tions of Fungi, I.," " The Boletaceae of North 

 America," " Notes on North American Hypo- 

 creales, I.," " A Bacterial Disease of the 

 Peach," " The Problems of North American 

 Lichenology " and " Notes and News." The 

 second number contains one colored plate of 

 agarics and three black-and-white plates, and 

 the text includes forty-six pages. The papers 

 are, "Illustrations of Fungi, II.," "The 

 Hypocreales of North America, II.," " Filling 

 Tree Cavities " and " Notes and News." 



The journal is well printed and is a worthy 

 continuation of the Journal of Mycology. 



At the moderate price of three dollars per 

 year it will, of course, be indispensable in 

 every botanist's library. 



LEO ERRERA 



Nearly four years ago the noted Belgian 

 botanist Leo Errera died in his forty-seventh 

 year. Born in 1858, he very early displayed a 

 brilliancy of mind which indicated what he 

 was to become in his maturity. Receiving his 

 doctorate from the university, he studied also 

 with Sachs, DeBary, Hoppe-Seyler, Waldeyer, 

 Stahl and others, and became personally ac- 

 quainted with Bower, Vines, Klebs, Schimper 

 and other noted botanists of Europe. Then 

 began a life of incessant activity, during 

 which he prepared and published nearly three 

 hundred papers. The earliest of these ap- 

 peared when he was but a youth of seventeen 

 years, while the last ten appeared within a 

 year or two after his death, after having been 

 completed by willing friends. 



There is now appearing in Brussels a col- 

 lection of the works of Errera under the title 

 " Recueil d'Oeuvres de Leo Errera " which 

 is to be completed in six volumes. The 

 papers thus brought together (and they are a 

 selection from all his publications) are of two 

 kinds, viz., (1) those addressed exclusively to 

 specialists in botany and physiology, and (2) 

 those intended for " non-specialists who read 

 and think." Those volumes have already ap- 

 peared, viz., I. and II., devoted to general 

 botany, and VI., containing miscellaneous 

 papers in prose and verse. The third volume 

 is to be devoted to general physiology, the 

 fourth to philosophy, while in the fifth will be 

 found i)edagogical and biographical papers. 

 The beauty of these volumes, their good 

 paper and clear type commend them as a fit- 

 ting memorial worthy of the man whom they 

 honor. Charles E. Bessey 



Univeesitt of Nebeaska 



SPECIAL ARTICLES 

 determination of the coefficient of 

 correlation 

 In statistical work it is often necessary to 

 determine the coefficients of correlation be- 

 tween a number of variables, the calculation 



