11 
PAGE 
Fragmentary Notes oil the Generative Organs of some Car- 
tilaginous Fishes. By John Davy, M.D., F.R.S. 
Lond. and Edin., &c., .... 392 
Donations to the Library, . . . .393 
Monday , 21 st January 1861. 
On a Method of taking Vapour Densities at Low Tempera- 
tures. By Dr Lyon Playfair, C.B., F.R.S. , and J. A. 
Wanklyn, F.R.S. E., .... 395 
Memoir of Sir Thomas Makdougall Brisbane. By Alex- 
ander Bryson, ..... 398 
Donations to the Library, . . . .398 
b 
Monday , Ath February 1861. 
Notes on the Snow Crystals observed during the late Frost. 
By Professor Allman. . . . ,399 
The Bifilar Magnetometer : its Errors and Corrections. By 
John Allan Broun, F.R.S., Director of the Trevaiv* 
drum Observatory. Communicated by Professor Tait, 406 
On the Horizontal Force of the Earth’s Magnetism. By 
John Allan Broun, F.R.S., Director of the Observa- 
tory of the Rajah of Travancore. Communicated by 
Professor Tait, ..... 407 
Notice of an Instrument intended for the Measurement of 
Small Variations of Gravity. By John Allan Broun. 
Communicated by Professor Tait, . . 411 
On the Law of Growth in Woody Circles of Exogenous 
Trees, as indicated by the Examination of a Single 
Specimen. By Principal Forbes, . . 412 
Donations to the Library, . . . .413 
Monday , 18i/i February 1861. 
On the Embryology of Asteracanthion Violaceus (Linn. 
Sp.) By Wyville Thomson, LL.D., F.R.S. E., 
M.R.I.A., F.G.S., &c., Professor of Natural History 
in Queen’s College, Belfast, . . .413 
[ For continuation of Contents , see pp, 3 and 4 of Cover. 
