276 NATURAL SCIENCE. April, 1895. 



unconscious memories, that they had slipped into the brain in some 

 forgotten time, eluding the gatekeeper, consciousness. Against this 

 view, he adduces the extraordinary vividness of the impressions : it 

 were unlikely that, as they impress us in dreams by their intrinsic 

 force, they would not have impressed the waking consciousnesss 

 when they first appeared. 



These two sides of the dreaming imagination, intense vividness 

 and apparently objective unexpectedness, Mr. Greenwood supports by 

 many examples. In some of these, dialogues in a dream leading to 

 surprising and unlooked-for ends, the impression of objectivity be- 

 comes so strong that Mr. Greenwood is led almost into a conception 

 of the actual objectivity of dream-impressions. He gropes vaguely, 

 on the one hand at the transference of thought from mind to mind 

 without the mediations of the known senses, on the other, at sugges- 

 tions of a dual personality, with their crude references to the bilateral 

 symmetry of the brain. But he stays himself from a full acceptance of 

 either notion. 



In his assured conclusion that the imagination is more active, 

 more creative if you will, in dreams than during waking hours, we are 

 in agreement with Mr. Greenwood. But we see no reason to suppose 

 that it invents materials. The treasures of the memory are unrolled 

 before it, rapidly, and without the distraction given in waking hours 

 through the open channels of the senses. To the seer in trances, to 

 the genius by conscious or unconscious abstraction, is given the 

 power of vividly working up accumulated materials ; the same power, 

 when the senses are partly or wholly drugged by sleep, is the common 

 lot of humanity. We are all geniuses and seers in our dreams. In 

 dreams the reason appears to lag behind the consciousness of 

 memories, and things appear external to us because of this dislocation. 



Mr. Lydekker's Royal Natural History, published by Frederick Warne 

 and Company, has now completed the history of the Mammalia and 

 commenced the birds. We trust the high standard attained by the 

 Mammalia will be kept up, and only wish that Messrs. Warne & Co. 

 would have the pluck to give us a general natural history of the 

 Invertebrata in as solid a form as they have the Mammalia. 



" A New Measure for Old Time," by An Amateur, is said to be an 

 easy method of finding the age of the earth's sedimentary crust, etc., etc. 

 This is how it is done. A period of 10,465 years being half the time 

 occupied by the earth in revolving about the line of the Apsides, was 

 obviously required for the deposition of each layer of limestone, shale, 

 or what-not in the crust of the earth. Multiply the number of layers 

 by this sum and you have the age of the earth, and the problem that 

 baffles physicists and geologists is solved. " Easy " is not the word 

 for it. 



The Glastonbury Antiquarian Society has reprinted as a shilling 

 pamphlet, published by Barnicott & Pearce, Taunton, various letters 

 and papers by Messrs. R. Munro, A. J. Evans, A. Bulleid, and 

 Professor Boyd Dawkins, on the British Lake-village near Glaston- 

 bury. The paper by Professor Boyd Dawkins appeared in our own 

 pages, in 1893. 



From Mr. Fisher Unwin there has come a small shilling 

 pamphlet, by Mr. Henry Larkin, on Elliptical Orbits, their dis- 

 tinctive mechanical characteristics and their possible origin. It is 

 out of our line, but some of our readers may be glad to learn of its 

 existence. 



