8 NATURAL SCIENCE. ^^^^h, 



Gregor}' has availed himself of the opportunity to revise the Echi- 

 noidea, while making an analysis of the evidence they provide as to 

 the age and origin of the Tertiary strata of Malta. The Echinoidea 

 always form a most valuable group, when evidence is required as to 

 the correlation of strata, or as to the conditions under which certain 

 sediments were laid down. Mr. Gregory comes to the conclusion that 

 the strata in question belong partly to the Oligocene, partly to the 

 Miocene period, and that they probably range from the Tongrian 

 (Lower Oligocene) to the Tortonian (Upper Miocene). The evidence 

 brought forward of changes of depth, as shown by the Echinoderms, 

 is curious. The Tertiary series in Malta begins and ends with shoal- 

 water deposits, but the intervening strata indicate deep water. 

 Other parts of the Mediterranean basin yield indications of a totally 

 different succession of events. It appears as if the earth-movements 

 on the shores of the Mediterranean have always been extremely 

 irregular. 



The origin of the " Parallel Roads " of Glen Roy is a question 

 of perennial interest to geologists, and Mr. T. F. Jamieson returns to 

 the subject in the February part of the Quarterly Journal of the 

 Geological Society. He refers the formation of the roads (or more 

 correctly beaches) to the action of lakes at different levels. These 

 lakes owed their existence to the ponding-back of the water in the 

 Glen by an ice-dam during the retreat of the last ice-sheet. The 

 accurate maps of the Glen made by the Ordnance Survey, and the 

 publications of the Danish Commission for the Exploration of Green- 

 land, show that Glen Roy was once, in all probability, singularly like 

 certain parts of Greenland, where ice-dammed lakes are still to be 

 found in several of the Fjords. 



Pleistocene botany is now attracting more attention. In 

 Nature (Jan. 21) Dr. A. G. Nathorst has brought forward "fresh 

 evidence concerning the distribution of arctic plants during the 

 Glacial Epoch," and gives a good map of Northern Europe showing 

 the localities from which the plants were obtained. In the Natur- 

 wissenschaftliche W ochenschrift (Jan. 24) Professor A. Nehring records 

 a number of plants from the " diluvial " deposits of the province of 

 Brandenburg ; these include the Holly and Hornbeam, and are not 

 arctic. 



The Cape Argus, of November 18, 1891 (as we learn from the 

 Kew Bulletin for January), announces that with the commencement of 

 the present year the Cape Town Botanic Garden will cease to exist 

 as a botanical establishment, and will be taken over by the municipal 

 authorities to be maintained as "a town pleasaunce of flowers and 

 shady walks." The director. Professor MacOwan, will be transferred 

 to the Agricultural Department as Government Botanist. He will 



