With insects of all kinds the males are commonly smaller than the females; and this difference can often be detected even in the larval state.

The bright colours of many butterflies and of some moths are specially arranged for display, so that they may be readily seen.

The male of the Cottus scorpius, or sea-scorpion, is slenderer and smaller than the female.

Almost all male birds are extremely pugnacious, using their beaks, wings, and legs for fighting together.

Birds possess acute powers of observation.

The truth and importance of the principle of inheritance at corresponding ages need not here be discussed, as enough has already been said on the subject.

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'They went on their way rather regardless of whether we understood them or not.'

I may here mention two very curious sexual peculiarities occurring in seals, because they have been supposed by some writers to affect the voice.

I am often undecided, Parmenides, as to whether I ought to include them or not.

European women are perhaps the brighter coloured of the two sexes, as may be seen when both have been equally exposed.

If any change has thus been effected, it is almost certain that the different races would be differently modified, as each has its own standard of beauty.

The development of the moral qualities is a more interesting problem.

Let us think of the mutual action between a magnet and a conductor.

Ten years later, in 1905, we find Einstein declaring that “the ether will be proved to be superfluous.”

The name of Prof. Albrecht Einstein has now spread far beyond the narrow pale of scientific investigators. Even now, it continues to do so.

At the present time, different opinions are being held about the fundamental equations of Electro-dynamics for moving bodies.

Now many authors say that classical mechanics stand in opposition to the relativity postulate, which is taken to be the basis of the new Electro-dynamics.

Theoretically, the human mind is the collection of all the electrical and chemical impulses of nerve cells, with their features and their interactions.

A short summary of the electromagnetic experiments bearing on this question, has already been given in the introduction.