RECENT ADVANCES IN SCIENCE 221 



were the Phoenicians because they worked out the richest 

 deposits of alluvial tin in Cornwall regardless of the con- 

 venience of Chicago and the requirements of the tinned meat 

 trade." 



The oil-field region of Egypt is near the Gulf of Suez, and 

 consists of a series of marls, salt, gypsum, and reef formations 

 of Miocene and Pliocene age. According to Hume's detailed 

 report, the most conspicuous oil indications are found in con- 

 nection with overfolded anticlines along both shores of the 

 Gulf of Suez. The richest supplies of oil occur in dolomitic 

 limestones associated with the Miocene gypsum deposits. 



The new memoir of the Geological Survey of Scotland is 

 the first of a series designed to present the economic geology 

 of the Central Coal-field. It deals principally with the coals, 

 and provides much new information as to the records of bore 

 and shaft journals, and other mining material collected during 

 the recent revision of the coal-field. Several maps are given, 

 showing the isopachytic lines for certain of the coal-seams. 



BOTANY. By E. J. Salisbury, D.Sc, F.L.S., East London College, 

 University, London. 



Ecology. — R. H. Boerker has carried out a number of experi- 

 ments upon the germination and early growth of tree seedlings 

 under varying conditions of light, water content, and soil 

 texture (Ecological Investigations upon the Germination and 

 Early Growth of Forest Trees. Lincoln, Nebraska, 1916). In 

 all some twenty-seven species were experimented upon. It was 

 found that in most cases shade accelerated the inception of 

 germination, a feature that may be attributed to the increase of 

 soil moisture which accompanies the diminution of light. In 

 addition the decreased illumination is accompanied by a pro- 

 longation of the germination period, and the final percentage 

 of seeds that germinate is usually higher in the shade than in 

 the light. 



Inadequate soil moisture was found to not only delay 

 germination and cause a decrease in the percentage of seedlings, 

 but to diminish the length of the germination period. It is 

 in harmony with these results that the more xerophyllous 

 species begin germinating first and have the shortest germination 

 period, whilst the reverse is the case with mesophyllous species. 

 In regard to soil texture, well aerated sandy soil was found to 

 15 



