Neanderthal man. Home sapiens neanderthalensis, a rather recently (perhaps 40,000 years ago) extinct sub-species of hominid from Pleistocene (mainly from early part of fourth glaciation about 100,000 years ago). Human brain size, with heavy brow ridges, low forehead, no chin prominence. Its remains are associated with more than one culture, but particulary Mousterian, which had ritual burial of dead.

Nearctic. Zoogegraphical region consisting of North America southwards to the middle of Mexico, and Greenland.

Nectary. Gland secreting sugary fluid (nectar) attractive to insects in many insect pollinated flowers.

Nekton. Swqimming animals of pelagic zone of sea or lake. Includes fishes and whales.

Nematode. Any member of the phylum Nematoda, containing round worms such as Ascaris

Neogene. The upper part of the Tertiary period including the Pleistocene. Pliocene and Miocene epochs.

Neoplarm. An autonous growth of tissue in the body which has no apparent physiological function, such as a tumour.

Neoteny. The retention of the juvenile body from or particular features of it, in a mature animal. For instance, the axololotl, a salamander, retains the gills of the larve in the adult. Neoteny is thought to have been an important mechanism in the evolution of vertain groups, such as man, who is believed to have developed from the juvenile form of apes.

Nephsidiopore. The external opening of a Nephridium.

Nephron. Excretory unit of vertebrate kidney, consisting of a Malpighian corpuscle and attached uriniferous tubule.