257 
had since then been much strengthened by some new facts. So far 
as he knew the earliest British Ammonite (A. planorbis) from the 
Lower Lias was the only species in that formation that had an 
Aptychus associated with it. The form of this was one-lobed, 
with coarse concentric lines of growth, and in this species an inner 
layer was always black, as if stained by some pigment. From the 
Saurian and Fish bed of the Upper Lias he had obtained micro- 
scopic Ammonites in which the Aptychus was seen far back in 
the outer chamber. A special form seems to be united to each 
species of Ammonite. On examining the moulds of A. serpen- 
tinus he found the surfaces covered with hundreds of thousands 
of minute “ eggs,” some apparently hatched. In some cases the 
siphuncular tube passes over the Aptychus, though not found in 
actual connection; the question then arose to him: “ What has 
the Aptychus and the tube to do with the eggs 1” Microscopic 
sections of various species revealed the fact that these were 
invariably cellular, and from these he extracted lines of cell tubes 
differing but little from the egg packets lying amidst the scattered 
eggs on the A. serpentinus. These facts seemed scarcely consis- 
tent with the operculum theory, and he ventured to suggest for 
the present at least that possibly the Aptychus with the siphun- 
cular tube is an Ovarian sac. 
At the Swansea Meeting in 1880, Charles Moore ventured to 
deal with that most difficult of the many geological questions, the 
presence of life in the Laurentian rocks of Canada. In his paper 
_ read before Section C. under the Presidency of Dr. Sorby, the 
great microscopist, he refers to the pleasure he had experienced 
during the Bath Meeting (1864) in assisting Sir William Logan 
the Director of the Canadian Geological Survey, to unpack the 
large polished block of Laurentian limestone, since deposited in 
the Jermyn Street Museum. After hearing the paper then given 
by Sir William on the presence of Eozoon Canadense (asserted 
to be the earliest form of life yet found in those 50,000 feet of 
rocks between the Cambrians and the base of the Laurentian 
