Page:Proceedings of the Royal Society of London Vol 4.djvu/493

Rh The following papers were read, viz. —

1. "Magnetic-term Observations for January, February, March, and April 1 843," made at the Observatory at Prague, by Professor Kreil. Communicated by Samuel Hunter Christie, Esq., Sec. R.S.

2. "Hourly Meteorological Observations, taken between the hours of 6 A.M. March 17th, 1843, and 6 a.m. of the following day, being the period of the Spring Tides of the Vernal Equinox, at Georgetown, British Guiana." By Daniell Blair, Esq., the Colonial Surgeon, transmitted by Henry Light, Esq. Communicated by the Lords Commissioners of the Admiralty.

3. " On the minute structure of the Skeletons, or hard parts of Invertebrata." By W. B. Carpenter, M.D. Communicated by the President. Part II. " On the structure of the Shell in the several families and genera of Mollusca."

The author here gives in detail the results of his inquiries into the combinations of the component elements of shell as they are met with in the several families and genera of the Mollusca ; and considers all these results as tending to establish the general propo- sition, that where a recognizable diversity presents itself in the ele- mentary structure of the shell, in different groups, that diversity af- fords characters which indicate the natural affinities of the several genera included in those groups, and which may therefore be em- ployed with advantage in classification, and in the recognition and determination of fossils.

The Society then adjourned over the Whitsun Recess, to meet again on the 15th instant.

The following papers were read, viz. —

1. " On the supposed developement of the Animal Tissues from Cells." By James Stark, M.D., F.R.S.E. Communicated by James F. W. Johnston, Esq., M.A., F.R.S.

The author controverts the prevailing theory of the developement of animal tissues from cells, and denies the accuracy of the micro- scopical observations on which that theory is founded, as regards the anatomy of the adult as well as of the foetal tissues. He asserts that at no period of foetal life can rows of cells be discovered in the act of transformation into muscular fibres : and he denies that these fibres increase either in length or in thickness by the deposition of new cells. He contends that the ultimate filaments of muscles, as well as all the other tissues of the body, are formed from the fibri- nous portion of the blood, which is itself composed of globules that are disposed to cohere together, either in a linear series, so as to form a net-work of fine filaments, or in aggregated masses of a form