26 



requires furtlier inquiry, as he finds that the same difference exists 

 between the poison-bags of the workers of these two insects. 



Crystals in the Seed-coats of Plants. — Eeferring to the crystals in 

 the testa of the elm, depicted by his father in the ' Quart. Joum. 

 Micros. Science,' vol. xiii., New Ser., Mr. Geo. GulLiTer exhibited 

 similar crystals in the same part of the gooseberry and sycamore 

 {Rihes grossularia and Acer pseudo-platanus) ; in the goosebeny 

 thickly studded throughout the seed-skin, and in the sycamore and 

 maple occurring in irregular patches that may not always be 

 readily found. His father had discorered similar crystals constantly 

 in the testa or pericarp in certain species of many orders, as 

 Papaveracese, Tiliacese, Aceracete, Geraniacege, Grossulariaceae, 

 Compositse, Primulacese, and Dioscoreaceae, whereas in the same 

 parts of numerous other orders such crystals are not present. 



July 10th, 1873. 



An excursion to the sea-side at Whitstable, when live specimens 

 were examined of Menbranipora, Plumularia, Laomedea, Alcyoni- 

 dium, ClaYeUna, Beroe, Cydippe, ^quoria, Eolis, Ifoctiluca, and 

 clusters of infant Balani — all under Colonel Horsley's, Mr. Sibert 

 Saunders's, Mr. Fullagar's, and Mr. R. J. Bell's microscopes. 



Development oj Oyster-spat. — Mr. Sibert Saunders described this, 

 illustrating it by live specimens under the microscope, from the 

 egg to the mature animal, and adding numerous interesting details 

 concerning its spawning and the habits and economy of the young. 

 "When the embryo is first extruded, and almost iavisible co the 

 naked eye, it has a complete bivalve shell, of which both valves are 

 convex, and not, as in the adult, one convex and the other flat. 

 The young oyster, as soon as parted from its parent, swims freely 

 about, by means of the cilia with which it is furnished even before 

 it is hatched ; and, after having become attached and fixed, it in- 

 creases in the course of two months to the size of a silver fourpence. 

 While swimmiag about, according to its habit, freely and viva- 

 ciously, the minute young oyster was shown to be a most curious 

 and interesting microscopic object. 



August 7th, 1873. 



Mrs. Dean contributed several specimens of some flowering plants, 

 which she had lately collected in the district. 



Teeth of Gasteropod Molluscs.— ^Colonel Horsley exhibited many 

 specimens of these in proof of their taxonomic value, and of their 

 excellence as objects for experiments with polarized light. 



Iron Ore at Whitstahle. — Captain McDakin presented samples of 

 ironstone taken from and near the railway-tunnel at Whitstable, 

 where the bed of ironstone is from two to four feet in thickness, 

 and is similar in appearance to, and of somewhat higher specific 

 gravity than, the famous iron ore of the Northampton sands. 



