146 Miscellaneoits. 



currence of conditions of an estuary nature, and leads to the inference 

 that the circumstance under which the silt was deposited approached 

 such as now prevails at the mouths of rivers. 



"The occurrence of marine forms of Diatoms in silt, puts us in 

 possession of another element, by means of which we are enabled to 

 ascertain the changes which have taken place in the physical geo- 

 graphy of the earth. It furnishes us with a means applicable in 

 many instances where other and more perfect organisms have disap- 

 peared, the siliceous skeletons of these minute bodies being capable 

 of resisting that agent by means of which the solid coverings of mol- 

 luscs are dissolved. ?>Iany of the raised sea-beaches, now affording 

 no shells, will probably be found to contain Diatoms, which will tell 

 of the conditions under which these raised sea-beaches were originally 

 deposited, and provide us with information concerning the circum- 

 stances which operated in the production of strata of this nature." 



Dr. Gregory alluded to the interesting fact that Diatoms had been 

 found by Ehrenberg in all fossiliferous rocks as far down as the 

 Silurian ; and that while the higher organisms exhibited striking dif- 

 ferences in the rocks of different epochs, there was, in the case of 

 Diatoms, a striking similarity. 



4. *' Notice of the time of Flowering of certain Trees and Shrubs 

 in the Royal Botanic Garden during the past month," by Mr. M'Nab. 



5. " Notes on the Effects of last winter upon Plants in the Royal 

 Botanic Garden, Belfast," by Dr. Dickie, Professor of Zoology and 

 Botany, Queen's College, Belfast. 



The lowest point to which the thermometer fell during the month 

 of February 1855 was on the 15th, viz. 13° F. In 1845, on March 

 5th, the thermometer in the Botanic Garden indicated 10° F., lower, 

 than in 1855. The injury to the plants, however, in 1855, was 

 greater, because in February last a generally low temperature, with 

 east and north-east winds, prevailed during two weeks. 



6. "Account of the Origin and of some of the Contents of the 

 Museum of Economic Botany attached to the Royal Botanic Garden 

 of Edinburgh," by Professor Balfour. 



MISCELLANEOUS. 



On the Organization of the Pedicellate Glands of the Leaf of 

 Drosera rotundifolia. By M. A. Trecul. 



There are some plants certain organs of which are capable of 

 executing very remarkable movements under the influence of a 

 mechanical excitement. Amongst these are the leaves of Mimosa 

 pudica and sensitiva, and of Dioncea muscipula, the stamens of Ber- 

 heris, &c. The Drosera has been classed with the plants which pos- 

 sess this singular property. It is generally supposed that as soon as 

 a fly or other insect, attracted by the viscous juice secreted by the 



