On communication noises used by domestic poultry.

Thanks for a letter describing variation in chickens.

Considers different animal instincts, some of which have reversed, others of which have proved persistent.

Has found prehistoric tools in his orchard that he believes have been buried by the action of earthworms.

CD thinks the celts [prehistoric tools] on the pan could not have been buried wholly by worms.

As for large size of Arctic mammals, CD suggests it is an advantage in retaining warmth.

Would like to cite the case of the celt in a new printing of Earthworms. Asks for details.

Describes the soil in which he found prehistoric tools.

Thanks CD for copy of Earthworms.