August 19, 1910] 



SCIENCE 



249 



second part of the third volume of Lacroix's 

 well-knowii " Mineralogie de la France," is the 

 announcement that the fourth and last volume 

 is now in press. This monumental description 

 of French minerals, the first part of which 

 appeared in 1893, will therefore soon be com- 

 plete. The present part, printed eight years 

 after the first part of volume 3, deals largely 

 with the carbonates, of which calcite naturally 

 takes the largest share. Starting in with the 

 description of the French occurrences of bru- 

 cite and hydrocuprite, the nitrates are taken 

 up (10 pages), to be followed by the carbon- 

 ates. These make up the bulk of the part be- 

 fore us, and the volume is concluded with an 

 appendix to the carbonates (whewellite and 

 mellite), an appendix of twelve pages and the 

 index to volume 3. The description of calcite 

 extends over about 170 pages and is illustrated 

 by 267 crystal drawings and photographs. 

 Then follow descriptions, replete with crystal 

 drawings, of the other rhombohedral carbon- 

 ates; giobertite (magnesite), mesitite and pis- 

 tomesite, siderite, dialogite (rhodocrosite), 

 smithsonite, dolomite and ankerite. The des- 

 criptions of these rhombohedral carbonates 

 cover nearly 250 pages, or over haK the book. Of 

 the orthorhombic carbonates the description 

 of aragonite is very full and richly illustrated. 

 Then follows witherite, strontianite and cerus- 

 site. A detailed description of ctypeite is 

 given and it is evident that Lacroix still holds 

 ctypeite as a third modification of CaCOo,, 

 distinct from calcite and aragonite, basing his 

 determination on the optical properties. Hy- 

 drozincite, aurichalcite, malachite, dawsonite 

 and bismuthite follow. The description of 

 chessylite (azurite) is naturally very full, 

 there being 56 illustrations of chessylite from 

 the classic locality at Chessy. Descriptions of 

 phosgenite, thermonatrite, natron, trona, nes- 

 quehonite and hydromagnesite close the vol- 

 ume. In the appendix may specially be noted 

 the descriptions of barytocalcite, bernonite of 

 Adam (Tableau miner., 1869) identified as a 

 variety of evansite, calcite (additional descrip- 

 tion), cristobalite and leesbergite (optically 

 homogeneous). A page of errata to the first 

 part of volume 3 is given. 



Waldem.ui T. Schaller 



Yorkshire Type Ammonites. Edited by S. S. 

 BucKMAN. Pt. I., pp. i-xii, ir-ii, plates 

 i-xi, and descriptions 1-8. London, Will- 

 iam Wesley & Son. 1909. Price 3s. 3d. 

 each part. 



The Jurassic ammonites of. Yorkshire to 

 the number of about 150 species were long ago 

 described by Young and Bird and by Martin 

 Simpson in a number of publications issued 

 from 1822 to 1855, with a second edition of 

 one of Simpson's works as late as 1884. 

 Young and Bird's descriptions were inade- 

 quate and only a part of them were accom- 

 panied by poor figures. Simpson's species 

 were published without illustrations. For- 

 tunately nearly all of the type specimens have 

 been preserved and Mr. Buckman is doing 

 paleontology a real service in the present 

 work by publishing faithful reproductions of 

 excellent photographs (by J. W. Tutcher) of 

 the types. The original descriptions are re- 

 printed and are supplemented by descriptive 

 notes and comments by the editor, who also 

 assigns the species to the numerous genera 

 and families that are now recognized and 

 contributes discussions of the genera repre- 

 sented. 



The work will be issued in about sixteen 

 parts, each of which will contain about twelve 

 to sixteen plates. The published first part 

 gives figures of eleven species belonging to 

 the genera Amaltheus, Uptonia, Platypleuro- 

 ceras, Barpoceras, Agassiceras, Oxynoticeras, 

 Harpoceratoides and Pseudolioceras. It is 

 evident that the work when completed will be 

 indispensable to paleontologists who have to 

 deal with Jurassic and especially Liassic am- 

 monites. T. W. Stanton 



SPECIAL ARTICLES 



ON THE INCREASED PERMEABILITY OF SEA URCHIN 



EGGS FOLLOWING FERTILIZATION 



In Science for July 22, 1910, McClendon 

 has shown that the permeability of the egg to 

 ions is greater after fertilization. He used an 

 electrolytic method. We wish to set forth 

 observations made during this summer, which 

 indicate that the increased permeability is not 

 confined to ions alone, and that it is more or 

 less specific for various substances. 



