i68 NATURAL SCIENCE. march. 



That of annuals and biennials is much prompter than of perennials, 

 while a much larger percentage of the former germinate, giving larger 

 and hardier seedlings. 



The percentage of germination was found to be greatest in 

 " persistent field weeds," only two of which, however, were studied ; 

 the Burdock and Dandelion ; that of wayside and fence-row weeds 

 like Elecampane (Inula Helenium) comes next, while in those which 

 cannot be characterised as weeds it is considerably less, the general 

 averages being 49, 33, and 8 respectively. This is taken as direct 

 evidence that the vitality of seeds of a species is a factor in determin- 

 ing its abundance and ability to become a weed. Twenty-five seeds of 

 each species studied were sown with the upper (pappus) end down- 

 wards, and a similar number erect ; 149 of the former germinated, 

 and 178 of the latter. The radicle emerges from the lower end, and 

 these numbers show that it is a disadvantage for this end to be upper- 

 most, a position, moreover, which the fruit would not naturally take, 

 since the pappus, acting like the feathers on an arrow, tend to keep it 

 erect. 



The Hidden Coal-fields in the South of England. 



Geologists who are interested in the study of the hidden coal- 

 fields in the South of England will find some exceedingly suggestive 

 remarks in two papers published by M. Marcel Bertrand. The 

 earlier one, though entitled " Sur la Continuite du Phenomene de 

 Plissement dans le Bassin de Paris " {Bull. Soc. geol. de France, ser. 3, 

 vol. XX., p. 118), relates largely to the anticlinal and synclinal folds 

 which cross the English Channel and North Sea. We are unable, 

 however, altogether to follow the author when he accepts the present 

 irregularities of the sea-bottom as corresponding to ancient undula- 

 tions in the strata beneath. It is so rare in our seas to find an 

 undisturbed rocky bottom, except near the Straits of Dover, and 

 shifting sand-banks are so common, that it seems more reasonable to 

 suppose that the irregularities of the sea-bed are mainly due to the 

 scour of the tide. Yet some of these irregularities are undoubtedly 

 ancient hills and valleys, or lines of escarpment. 



M. Bertrand's second paper, " Sur le Raccordement des Bassins 

 Houillers du Nord de la France et du Sud de I'Angleterre " (Ann. 

 des Mines, Jan., 1893), deals mainly with the hidden coal-fields, their 

 probable position, and their extent. The maps published with these 

 papers are excellent, and ought to throw a great deal of light on the 

 trend of the Coal-measures in our southern counties. 



W'e would also direct attention to Mr. Brady's report on the 

 Dover Coal Boring, reviewed elsewhere. 



Prehistoric Archaeology. 

 The " Congres International d'Archeologie Prehistorique," 

 which met last year at Moscow, has led to the publication of an in- 



