14 
case, as in the spores, the pro-embryo of the second generation 
was formed. 
The paper was illustrated Ly drawings and bryological speci- 
mens prepared by Mr Smiru, and exhibited under microscopes by 
the following gentlemen :— 
Among the most striking were Mniwm cuspidatum, her- 
maphrodite flowers, showing archegonia, antheridia, and para- 
physes ; Neckera oligocarpa, female flowers, consisting of archegonia 
and paraphyses; Mnium hornum and Polytrichum commune, 
by Mr Hennau, shewing male flowers. 
Cinclidium Stygiwm, with cupuliform peristome, Ceratodon 
purpureus, peristome with divided teeth; section and leaf of 
Polytrichum formosum, covered with papille ; Ephemerum serra- 
tum, with prothallus and young buds, by Mr. Suiru. 
Pottia cavifolia, section of leaf exhibiting layers ; O17 thotrichum 
Lyellii with confervoid gemmee on the leaves—this is the conferva 
castanea of the early botanists ; Sphagnum acutifoliwm, exhibiting 
two sets of cells, one set containing spirals, by Mr Sewett. 
Aulacomnion androgynwm, showing gemmee on ‘‘pseudopodia,” 
Ulota phyllantha, with gemme on the tips of the leaves—in this 
case the gemme are aggregated cells; and Tetraphis pellucida, in 
which the gemmez are enclosed in a lenticular bud, by Mr Wonror. 
January 13th, 1870.—‘‘ On Volcanic Theories,” by Mr. J. HE. Mayatt. 
If science were nothing more than a registry of facts, it would 
still be a degradation to assign everything to a special cause, a plan 
pursued in the past, and which had led to extravagant theories. 
It was well known that no one branch of science could be taken 
alone, but in relation to others ; the study of geology was connected 
with the astronomical motions of the earth, and volcanic action 
was intimately allied to astronomy. 
Taking the ideas of Laplace respecting the extent of the solar 
atmosphere, and the manner in which nebulous matter would break 
off into zones, which, on cooling, would assume the spheroidal 
