220 
Mr. Cameron exhibited the following fungi : — 
Entorrhiza cypericola, Weber, from near Entwistle. This 
species forms tumours on the roots of various species of 
Juncus, and has been found in different localities in Scot- 
land, but has not been previously recorded from England. 
Tetramyxa parasitica, Goebel, from Ayrshire. This fun- 
gus gives origin to gall-like masses on the stems of Ruppia 
maritima, var. rostellata. The galls are irregular in shape, 
have a diameter of from 2 to 3J lines, and are greenish or 
yellowish in colour, but become brownish with age. The 
species, in all probability, belongs to the Myxomycetes, and 
is distinguished, inter alia, from the known genera of that 
group by the spores being formed by quadripartition. This 
is the first record of the species in Britain. 
Mr. W. Blackburn, E.B.M.S., read a paper on the De- 
velopment of Bone. 
In a very early condition of the embryo, the parts which 
are afterwards to become bone consist of elementary cells, 
very similar to those found in other parts of the embryo. 
Unlike the latter, however, they soon become transformed 
into cartilage, and in this substance the process of ossifi- 
cation at length takes place. All the bones of the body are 
formed in cartilage, except the tabular bones of the skull, 
which are formed in fibrous membrane. The process is some- 
what similar in each case. Bone is always formed in a pre- 
existing substance, either cartilage or membrane. It is not, as 
was formerly supposed, the result of the deposit of calcareous 
particles in such a substance, and the metamorphosis of its 
cells into the corpuscles of bone. But this transformation 
usually takes place by means of another set of cells, to which 
Gegenbaur gave the name of osteoblasts, which are developed 
from the previously existing cells of cartilage or connective 
tissue. The paper described the alteration which takes 
