184 
England, during the post-glacial epoch. How long ago it 
is impossible to guess, because the geological past cannot 
be measured by the historical unit of years. A detailed 
account of the exploration of the first three years is to be 
found in Quart. Geolg. Journ., London, Yols. xviii. p. 115, 
and xix. p. 260. 
“ On the Germination and Early Growth of Plants,” by 
Arthur Ransgme, M.D., M.A. 
The following statement with reference to the conditions 
of growth was quoted from Prof. Draper’s works : — “ If 
growth be conducted in darkness, heat, air, and water can- 
not cause the young plant to add anything to its substance. 
It is feeding on the seed. Indeed, when the experiment is 
carefully made, it is found that there is an actual loss of 
substance, the resulting plant, if dried, weighing less than 
the dry seed from which it came Growth in 
darkness leads to one result, and growth in the sunshine 
to another .” — Human Physiology, 1856, p. 458. 
The truth of this observation was tested as follows 
Given weights of fresh mustard seed were taken, each 
portion was divided into two equal parts ; one part of each 
was crushed and moistened, to set free any volatile oil, and 
then carefully dried in a water-bath, or in Dr. Calvert’s 
silk conditioning apparatus which he kindly allowed to be 
used ; the other portions were sowed upon well- washed old 
flannel, placed upon inverted saucers, and watered with 
distilled or town’s water. The experiments were carried on 
through the months of June, July, and August of 1858. In 
four instances, the seeds were left to the full influence of 
diffused daylight. In two others the saucers were placed 
in a perfectly dark cupboard, and watered at night by 
artificial light ; and in one case the seeds were placed in a 
dark wine cellar. After growth the plants were carefully 
dried and weighed. 
