REPORTS OF SOCIETIES. 
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theory which is now generally accepted, he exhibited some specimens 
of Philodina roseola , which had been dried on paper and sent to him per 
post by Rev. E. J. Holloway, of Clehanger, and some of which being 
revived by placing in water could be seen under the microscope 
in the full vigour of life. Mr. T. Bolton exhibited Gordylophora lacustris , 
also various freshwater diatoms, including some fine Nitzschia sigmoidea. 
—Sociological Section, March 18tli.—Mr. F. J. Cullis discoursed on 
Part IV. of the second volume of Mr. Herbert Spencer’s “Principles 
of Biology” on “ Morphological Development,” passing in rapid review 
the opening chapters on “ Morphological Composition of Plants and 
Animals,” dwelling at length on the later chapters on “ Morphological 
Differentiation,” and expounding exhaustively the thirteenth chapter 
on “ Morphological Differentiation in Animals.” His most interesting 
and lucid address, of an liour-and-a-half’s duration, was listened to 
with close attention by the members of the section present. In 
illustration of the modification and differentiation produced by 
environment, Mr. W. R. Hughes, F.L.S., president of the section, 
exhibited under the microscopes specimens of Palcemou serratus, the 
common prawn, and of Bopyrus squillarum, its parasite, both of which 
it is assumed have originated from a common progenitor. 
BIRMINGHAM MICROSCOPISTS’ AND NATURALISTS’ 
UNION.—February 22nd. Mr. Moore showed the following land and 
freshwater shells from America: —Helix albolabris , H. alteriata, H. 
manselen, and Limnophysa rejlexa; Mr. C. Neville, specimens of tufa 
and fossil wood from Portland; Mr. Evans, transverse section of the 
jaws of an ichthyosaurus, the intermediate space being filled with iron 
pyrites. A paper was read by Mr. Hutchinson on “ Yeast fungi and 
their functions,” which reviewed the history of observations on this 
subject, showing that although the minute cells of the yeast plant 
were known in the seventeenth century, really accurate knowledge 
could only be gained after great improvements in the microscope. The 
paper described the yeast of commerce as mainly a Continental 
product. The various forms and sizes of cells were spoken of as being 
largely dependent on the suitableness of the fluid they lived in; the 
small oval cells were said to be most valuable for bread making. 
The paper was illustrated by experiments and specimens of the plant 
under the microscope.—March 1st. Mr. J. E. Bagnall presented to 
the society a copy of his “ Handbook of Mosses.” Under the micro¬ 
scope Mr. Hawkes showed llcestelia cornuta, on mountain ash leaf, from 
Scotland; Mr. J. W. Neville, gizzard of mole cricket, Gryllotalpa 
vulgaris. —March 8th. A paper was read by Mr. Evans on “ Volcanoes 
and volcanic action,” describing the many erroneous ideas respecting 
them that had come down to us from olden times. A volcano was 
simply a fissure in the earth’s crust where a molten interior found a 
vent. The phenomena of an eruption were described, Stromboli 
(which was said to be a pocket edition of a volcano) being given as a 
type. Volcanoes were either active, quiet, or extinct; the number of the 
first was computed at about 320. The paper reviewed the different 
theories of volcanic action as coming within the province of the 
astronomer, chemist, and geologist, and concluded by showing 
that evidences of eruptions were as old as the world, and 
that these furious outbursts were only specks in the universe on 
which all mankind depends. The paper was illustrated with 
diagrams, minerals, Ac. A discussion closed the meeting.— 
March 15th. Mr. Collins exhibited a collection of minerals, including 
