504 



SCIENCE. 



[N. S. Vol. XV. No. 378. 



the attacks of snails and browsing cattle. Our 

 observations in the North African area, from 

 Morocco to Egypt, on the edge of the Sahara 

 in southern Algeria, and in Palestine, lead us 

 to fully endorse the view of the Rev. Dr. 

 Ilenslow, that in desert areas where plants are 

 especially spiny or thorny, there are few 

 snails, and a general absence of cattle. Over 

 a century ago Pallas, and afterwards L. Eeg- 

 nier, in a paper published in 1792 (II., p. 

 101) in the very rare Journal d'Hisioire Na- 

 turelle, edited by Lamarck and others, attrib- 

 uted the spiny growth of desert plants to the 

 dryness of the soil. His observations appear 

 to have been entirely overlooked by modern 

 writers. A second article (p. 354), written by 

 De Ramatuelle, is thoroughgoing in its evolu- 

 tional tone, barring perhaps the speculations 

 as to the origin of the spines from 'gcrmes 

 particuliers.' 



Professor Beecher's splendid discovery of 

 llie nature of the appendages of trilobites and 

 of other important points in their anatomy 

 has entitled him to the lasting gratitude both 

 of paleontologists and zoologists. This 

 reprint of his original papers and illustra- 

 tions is very opportune. It is possible, how- 

 ever, that the last word has not been said as 

 to the nature of the larval trilobites or as to 

 the position of the trilobites in nature. How 

 the protaspis stage of trilobites can be likened 

 to the nauplius of Crustacea, and why trilo- 

 bites should be placed among Crustacea, we do 

 not understand. That the presence of anten- 

 nae necessarily obliges us to regard trilobites 

 as Crustacea, when all the succeeding append- 

 ages of the body are of the same general type, 

 not being differentiated into specialized man- 

 dibles, maxillas, maxillipedes, thoracic and 

 abdominal legs, as they are in Crustacea, in- 

 cluding the Phyllopoda (though in them the 

 appendages of the trunk are alike), does not 

 seem logical. We would prefer to regard the 

 trilobites, merostomes and Arachnida as mem- 

 bers of a phylum quite distinct from that of 

 the Crustacea. Is it not probable that the 

 rather artificial phylum of Arthropoda will 

 eventually have to be divided into three phyla ? 

 The resemblances in trilobites to Crustacea 

 seem to us to be a case of convergence. The 



papers on Brachiopoda are likewise of great 

 interest and value, and are crowded with val- 

 uable suggestions. The line of thought is 

 largely based on the work of the late Dr. A. 

 Hyatt, whose philosophical and scholarly 

 niethods have had such a happy and fruitful 

 influence on the new generation of paleontolo- 

 gists. 



A. S. Packard. 



SOCIETIES AND ACADEMIES. 



THE AMERICAN PHILOSOPHICAL SOCIETY. 



The scientific program of the general meet- 

 ing to be held next week is as follows : 



Thursday, April 3, 10:00 o'clock. 

 ' The President's Address ' : Gen. Isaac J. 



WiSTAR. 



' Origin of the Oligooene and Miocene Deposits 

 of the Great Plains ' : Professor John B. 

 Hatcher, of Pittsburg. 



' The Upper Cretaceous and Lower Tertiary 

 Section of Central Montana ' : Mr. Earl Douglass, 

 of Princeton. 



' Evolution and Distribution of the Proboscidea 

 in America ' : Professor Henry F. Osborn, of 

 New York. 



' On South American Mammals ' : Professor 

 WiLLiAii B. Scott, of Princeton. 



' The Mammals of Pennsylvania and New Jer- 

 sey ' : Mr. Samuel N. Rhoads, of Audubon, N. J. 



' The Identity of the Whalebone Whales of the 

 Western North Atlantic ' : Dr. Frederick W. 

 True, of Washington. 



Afternoon Session, 2:00 o'clock. 



' On the Molluscan Fauna of the Patagonian 

 Formation': Dr. H. VON Ihering, of Sao Paulo, 

 Brazil. 



'A Comparison Between the Ancient and Recent 

 Molluscan Fauna of New England ' : Professor 

 Edward S. Morse, of Salem, Mass. 



' Distribution of Fresh Water Decapods and its 

 bearing upon Ancient Geography ' : Arnold E. 

 Ortmann, Ph.D., of Princeton. 



' Systematic Geography ' : Professor William 

 Morris Davis, of Cambridge, Mass. 



' On Drift Casks in the Arctic Ocean ' : Mr. 

 Henry G. Bryant, of Philadelphia. 



' The Isthmian Canals ' : Professor Lewis M. 

 Haupt, of Philadelphia. 



