n8 SCIENCE PROGRESS 



quartz ores occur. Geijer upholds the theory of sedimentary 

 origin for ores of this type. The great iron-ore bodies of 

 Lapland are regarded as due to magmatic differentiation, and 

 are compared with those of Iron Mountain and Pilot Knob, 

 Missouri. 



The Oriskany (Silurian) iron ores of Virginia are described 

 by C. M. Weld (ibid. 399) as having originated as syngenetic 

 bog-iron deposits in the Oriskany Sandstone. Subsequent 

 solution and replacement by meteoric waters has concentrated 

 and enriched the original deposits. 



The same author discusses the ancient sedimentary iron 

 ores of British India (ibid. 435). The universal character of 

 this series is the presence of banded haematite-magnetite- 

 quartz rocks, in which the pure ores range in size from mere 

 films to great tabular lenses. They are interbedded with 

 ancient unfossiliferous sediments (Dharwar) corresponding in 

 stratigraphical position with the Huronian of America. They 

 are regarded as slightly metamorphosed sedimentary ores, and 

 are strikingly like the Pre-Cambrian itabirite ores of Brazil. 



ZOOLOGY. By Charles H. O'Donoghue, D.Sc, F.Z.S., University 

 College, London. 



Protozoa. — To the work commenced by Hickson and Wadsworth, 

 Lapage and Wadsworth have added Dendrocometes paradoxus 

 (Stein), Part II. Reproduction (Bud-formation) (Quart. Jour. 

 Micro. Sci. vol. lxi. March 191 6). This form of reproduction 

 takes place by internal budding, and only one bud is produced 

 at a time. The accompanying nuclear changes are dealt with. 

 In an investigation of "The Gregarines of Glycera siphonostoma " 

 (Quart. Jour. Micro. Sci. vol. lxi. March 191 6) Pixell-Goodrich 

 has found four distinct species, including one Gonosporan. 

 This species, Gonospora glycerol, sp. n., whose spores are more 

 complicated than is generally the case in the genus, is sur- 

 rounded by a layer of host epithelium during most of its life, 

 and association is accomplished by a characteristic dove-tailing. 

 The nuclear and cytological changes that accompany the pheno- 

 menon known as endomixis form the subject of a paper, " The 

 Periodic Reorganisation Process in Paramecium caudatum " 

 (Jour, of Exper. Zool. vol. xx. February 191 6), by Erdmann and 

 Woodruff. Nearly fifty years ago bottles of soil were stored 

 at Rothamsted Laboratory, and two new species of Amoeba 



