GLOSSARY. 285 



Nauplius. The earliest larval form of Crustaceans. 



Nectocalyx. The swimming-bell of a Medusa. 



Nematocysts, Trichocysts, or Cnidce. Peculiar cells in the Acti- 

 nozoa containing thread-like bodies having a stinging or urti- 

 cating power. 



Ncmatophores. Appendages of the coenosarc of Plumulariidae con- 

 taining thread-cells. 



Neossology. The study of the nestlings of birds. 



Nervures. The hollow tubes supporting the wings of insects, and 

 acting as organs of circulation and respiration. 



Neural. Eclating to the nervous system. 



Neurapophyses. The spinous processes of the vertebrse. 



Neurilemma. The membrane investing a nerve. 



Neuroglia. The connective network of the eye. 



Neuropodium. The ventral portion of the parapodium of an 

 Annelid. 



Nisus formativus. One of the old-fashioned phrases, "self-de- 

 ceiving, world-beguiling simulacra of science." 



Nomogeny. The law of coming into being, i. e. of creation. 



Noth&um. (Qu. j/wros or voQos ?) A name for the mantle of the 

 Mollusca. 



Notochord or chorda dorsalis. "A cellular rod which is developed 

 in the embryo " of the Vertebrata, and is ultimately replaced 

 by the spinal cord. 



Notopodium. The dorsal portion of the parapodium of an Annelid. 



Nucleolus. A minute particle in the middle of the nucleus. In 

 the ovum it is the " germinal spot." 



Nucleus. The central particle in the elementary cells of animal 

 tissues. In the ovum it is the " germinal vesicle." 



Nymph. The active pupa of certain insects. 



Ocelli or stemmata. Simple or supplementary eyes in insects and 

 spiders. 



Odontophore. See Radula. 



(Ecoid. A name for a blood-disk. 



(Edagus. The membrum virile of insects. 



(Esophagus. The gullet, connecting the mouth to the stomach. 



Omostegite. The posterior portion of the dorsal plate of a Crus- 

 tacean. 



