16 NOTICES OF THE MEETINGS. [Feb. 7, 1851. 
in the body of the first individual developed from that germ-mass, 
with so much of the pollen-force inherited by the retained germ- 
cells from the parent-cell or germ-vesicle as suffices to set on foot 
and maintain the same series of formative actions as those which 
constituted the individual containing them. 
How the retained pollen force operates in the formation of a new 
germ-mass from a secondary, tertiary, or quaternary derivative germ- 
cell, the Lecturer did not profess to explain; neither was it known 
how it operates in developing the primary germ-mass. 
The botanist and physiologist congratulates himself with justice 
when he has been able to pass from cause to cause, until he arrives 
at the union of the pollen-filament with the ovule as the essential 
condition of development—a cause ready to operate when necessary 
circumstances concur, and without which those circumstances would 
have no effect. 
The chief aim of the present discourse was to point out the cir- 
cumstances which bring about the presence of the same essential 
cause in the cases of the development of the successive generations 
completing the metagenetic cycle of the Aphis, the Medusa, the 
Polype and the Entozoon. The cause is the same in kind though 
not in degree, and every successive generation, or series of sponta- 
neous fissions, of the primary germ-cell must weaken the pollen-force 
transmitted to such successive generations of cells. 
The force is exhausted in proportion to the complexity and living 
powers of the organism developed from the primary germ-cell and 
germ-mass. It is consequently longest retained and furthest trans- 
mitted in the vegetable kingdom; the zoophytes manifest it in the 
next degree of force; and the power of retained germ-cells to de- 
velope a germ-mass and embryo by the remnant of the pollen-force 
which they inherited, is finally lost, according to present knowledge, 
in the class of Insecta and in the lower Mollusca. 
° 
Among the objects exhibited in the Library, were— Edwards’ 
Atmopyre or Gas Stove [by D. O. Edwards, Esq., M.R.I.] — Sketch 
of Coldham-hall, near Bury St. Edmunds, reproduced as a Photo- 
graph, coated with a solution of Gun-Cotton; and several other 
Photographs from Etchings &c.—and a group of Garnets in Mica 
Schist from the Rocky Mountains, North America [by Dr. A. S. 
Taylor, M.R.I.]— Specimens of Sugar of Milk [by T. N. R. Mor- 
son, Esq., M. R. I.— Model of the Nineveh Column in the British 
Museum, in Hall’s Derbyshire black marble [by J. Tennant, Esq. ] 
&c. &e. 
