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chord, or with the cerebro-spinal nerves, 

 by very small filaments, and they have nu- 

 merous ganglions throughout their course ; 

 they preside over the nutritive functions, 

 upon which the mind has no direct in- 

 fluence : these are the nerves of organic life, 

 or ganglionic or great sympathetic nerves. 

 The cerebro-spinal nerves convey impres- 

 sions from their extremities to the brain, 

 and they also convey the influence of 

 the will from the brain to the voluntary 

 muscles ; these passing and repassing, or 

 receptive and remissive influences, are 

 conveyed by distinct sets of nervous fila- 

 ments, which, however, are generally 

 enclosed in the same sheath, and there- 

 fore appear to form a single nerve." 

 Brandt. 



" Experience has shown us," observes 

 Mr. Newman, " that, on the brain of inver- 

 tebrated animals being separated from the 

 body, or even greatly injured, both sensa- 

 tion and active vitality at once cease ; but 

 in insects the separating of the head or of 

 the parts containing either of these masses 

 of nerves, produces no immediate or ascer- 

 tainable effect on sensation or vitality. 

 This shows us, first, that mind or volition 

 is, in vertebrated animals, situate in the 

 brain ; secondly, that in insects it is not 

 confined to any part. These conclusions 

 lead to the probability of a third, that 

 brain and nerve are but different states of 

 the same system of organs. The vitality, 

 therefore, concentrated in a brain, may be 

 diffused through the nerves when there is 

 no brain, and each mass of nerves may be 

 the seat of that small power of mind which 

 insects possess." 



NKUVURES. The delicate frame- work of the 

 membranous wings of insects. 



NEURILEMMA. The membrane which sur- 

 rounds the nervous fibre. 



NEUROLOGY. The science of the nervous 

 system, or a description of the nerves. 



NEUROPTEROUS. Belonging to the Neurop- 

 tera, an order of four-winged insects, cha- 

 racterized by their numerous nervures, like 

 those of the dragon-fly. 



NEUROSE. Wings of insects that have 

 nervures besides the marginal ones. 



NEUROTOMY. The art or practice of dissect- 

 ing the nerves. 



NIBBLE. To bite at ; as, fishes nibble at the 

 bait. A little bite, or seizing to bite. 



NICTATING (membrane). The thin mem- 

 brane that covers and protects the eyes of 

 some animals, without entirely obstructing 

 the sight. 



NIDAMENTAL. Relating to the protection 

 of the egg and young, especially applied 

 to the organs that secrete the material 

 of which many animals construct their 

 nests. 



NIDIFICATION. The act or operation of 

 building a nest, and the hatching and feed- 

 ing of young in the nest. 



NIDULATION. The time of remaining in the 

 nest. 



NIDUS. A nest or repository for the eggs of 

 birds, insects, &c. 



NOCTIDIAL. Comprising a night and a day. 



NOCTILUCOUS. Shining in the night. 



NOCTIVAOANT. Wandering or prowling 

 about by night. 



NOCTURNAL. Pertaining to the night, as the 

 nocturnal habits of certain animals which 

 usually come forth from their retreats and 

 obtain their prey during the night. 



NODOSE. Having one or more knobs or 

 swellings. The word Nodose is also ap- 

 plied to the antennae, of insects when they 

 have one, two, or more joints larger than 

 those which precede or follow them. 



NODULAR. Pertaining to, or resembling, a 

 nodule or little knotty lump. 



NODULE. A little knot-like eminence. 



NOMADIC. Wandering for the sake of pas- 

 turage ; pertaining to a pastoral life, and 

 roving from place to place with herds of 

 cattle. 



NOMENCLATURE. The names of things which 

 are appropriated to any branch of science. 



NONAGK. Under adult age. 



NONDESCRIPT. Anything that has not been 

 described. Thus an animal newly disco- 

 vered is called a nondescript. 



NONFOSSILIFEROUS. Not producing fossils ; 

 of a nature not to convert into fossils. 



NORMAL. According to rule ; natural. 



NOSTIULS (of birds) are said to be linear, 

 when they are extended lengthwise in a 

 line with the bill, as in Divers, &c. ; per- 

 vious, when they are open, and may be seen 

 through from side to side, as in Gulls, &c. 



NOTAL. Belonging to the back. 



NUCLEATED. Having a nucleus or central 

 particle : applied to the elementary cells 

 of animal tissues, the most important pro- 

 perties of which reside in the nucleus. 



NUDIBRACHIATA. The Polypes whose arms 

 are not clothed with vibratile cilia. 



NUDIBRANCHIATA. An order of Gasteropods 

 in which the gills are exposed. 



NUMMULITE. Fossil remains of a chambered 

 shell of a flattened form, formerly mistaken 

 for money. 



NUTRIENT. Nourishing ; producing growth. 



NYMPH. The pupa or chrysalis ; the second 

 state of an insect, passing to its perfect 

 form. 



OBESE. Unnaturally large and distended, 

 as if from disease or too much food. 



OBLIQUE. Running sideways : when the 

 longitudinal line is cut through at acute 

 angles. 



OBLITERATE. A term in entomology ap- 

 plied to impressions and elevations when 

 almost effaced. 



OBLONG. Longer than broad : the longi- 

 tudinal diameter being more than twice the 

 length of the transverse, and the ends vary- 

 ing, or rounded. 



OBLONG-OVATE. Between oblong and egg- 

 shaped. 



OBSCURK. A surface which reflects the light 

 but little. 



OBSOLETE. Partially indistinct ; not well- 

 defined ; not fully developed ; as the faint 

 striae on certain shells. 



OBTRUNCATED. Lopped off; deprived of a 

 limb. 



OBTUSE. Blunt ; not pointed or acute ; dull ; 

 obscure : terminating bluntly, but within 

 the segment of a circle. 



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