… the embryological record, as it is usually presented to us, is both imperfect and misleading. It may be compared to an ancient manuscript, with many of the sheets lost, others displaced, and with spurious passages interpolated by a later hand. … Like the scholar with his manuscript, the embryologist has by a process of careful and critical examination to determine where the gaps are present, to detect the later insertions, and to place in order what has been misplaced.

A solid heavier than a fluid will, if placed in it, descend to the bottom of the fluid, and the solid will, when placed in the fluid, be lighter than its true weight by the weight of the fluid displaced.

Any solid lighter than a fluid will, if placed in the fluid, be so far immersed that the weight of the solid will be equal to the weight of the fluid displaced.

Every great scientist becomes a great scientist because of the inner self-abnegation with which he stands before truth, saying: “Not my will, but thine, be done.” What, then, does a man mean by saying, Science displaces religion, when in this deep sense science itself springs from religion?

In scientific study, or, as I prefer to phrase it, in creative scholarship, the truth is the single end sought; all yields to that. The truth is supreme, not only in the vague mystical sense in which that expression has come to be a platitude, but in a special, definite, concrete sense. Facts and the immediate and necessary inductions from facts displace all pre-conceptions, all deductions from general principles, all favourite theories. Previous mental constructions are bowled over as childish play-structures by facts as they come rolling into the mind. The dearest doctrines, the most fascinating hypotheses, the most cherished creations of the reason and of the imagination perish from a mind thoroughly inspired with the scientific spirit in the presence of incompatible facts. Previous intellectual affections are crushed without hesitation and without remorse. Facts are placed before reasonings and before ideals, even though the reasonings and the ideals be more beautiful, be seemingly more lofty, be seemingly better, be seemingly truer. The seemingly absurd and the seemingly impossible are sometimes true. The scientific disposition is to accept facts upon evidence, however absurd they may appear to our pre-conceptions.

It is possible that in ten years’ time penicillin itself will be a back number and will be replaced by something better. It is quite certain though that to displace penicillin any newcomer will have to be very, very good.

Memory is a fascinating trickster. Words and images have enormous power and can easily displace actual experience over the years.

The forces which displace continents are the same as those which produce great fold-mountain ranges. Continental drift, faults and compressions, earthquakes, volcanicity, transgression cycles and polar wandering are undoubtedly connected causally on a grand scale. Their common intensification in certain periods of the earth’s history shows this to be true. However, what is cause and what effect, only the future will unveil.

The world won’t come to an end, but the incidence of disasters will have a very big impact, and in ways we can't predict. … Rises in seas levels will displace millions of people. It’s estimated there will be 150 million refugees by 2050, homeless as a result of global warming. It’s how we deal with these problems that is as much the challenge as tackling the causes of global warming.