Nilghau, sexual differences of colour in the.

Nilsson, Prof., on the resemblance of stone arrow-heads from various places; on the development of the horns of the reindeer.

Nipples, absence of, in Monotremata.

Nitsche, Dr., ear of foetal orang.

Nitzsch, C.L., on the down of birds.

Noctuae, brightly-coloured beneath.

Noctuidae, coloration of.

Nomadic habits, unfavourable to human progress.

Nordmann, A., on Tetrao urogalloides.

Norfolk Island, half-breeds on.