MYXOTHECA 



834 



NAIL 



oxopoQ, seed]. A group or order of Sporozoa, found 

 as parasitic bodies in the muscles and epithelia of fishes ; 

 they produce a psorospermosis which is frequently 

 wide-spread and destructive. 

 Myxotheca (niiks-o-the' -kali) \jivi-a, mucus ; Orjuj], a 



sheath: pi. , Myxotheca\. In biology, the honrj 

 sheath of the tip of the lower mandible of a bird. 

 Myzesis (nii-ze'-su) [fiv&iv, to suck]. Synonym of 

 sucking. 



IN 



N. The symbol of nitrogen ; also, the sign of the index 

 of refraction. 



N. A. Abbreviation for numerical aperture. 



N. F. National Formulary; a collection of formulas 

 issued by the American Pharmaceutical Association as 

 a kind of supplement to the U. S. Pharmacopeia. 



Na. Symbol of natrium or sodium. 



Ni. The symbol for nickel. 



Nabalus (nab'-al-us) [ya t 3?ia, a harp]. A genus of 

 composite-flowered plants ; by some considered a sec- 

 tion of Prenanthes. There are many American 

 species, called drop-flower artd rattlesnake-root. A 

 poultice of the pounded fresh leaves of N. altissimus, 

 or " white lettuce," of N. America, has been used as 

 an application to ulcers, gangrenous sores, etc. Unof. 



Naboth, Cysts of, N., Glands of. See Gland. N.'s 

 Menorrhagia, a serous discharge from the vagina in 

 pregnant women. 



Nabothian Ovule {iia-bo* -the-aii). See Ovule. 



Nacre (na'-ker) [Ar., nakir, hollowed out]. Mother- 

 of-pearl. 



Nacreus {na'-kre-us) [Ar., nakir, hollowed out]. Re- 

 sembling nacre or mother-of-pearl. 



Naegele's Fluids. Fluid culture-media. I. Water 

 IOO c.c, ammonium tartrate I gm., potassium biphos- 

 phate o. I gm., magnesium sulphate 0.02 gm., cal- 

 cium chlorid o.oi gm. 2. Water ioo c.c, albumin- 

 peptone I gm. , potassium biphosphate 0.2 gm. , mag- 

 nesium sulphate 0.04 gm., calcium chlorid 0.02 gm. 

 3. Water ioo c.c, cane-sugar 3 gm. , ammonium tar- 

 trate I gm. , potassium bitartrate o. 21 gm. , magnesium 

 sulphate 0.04 gm., calcium chlorid 0.02 gm. Filter 

 and sterilize. N.'s Obliquity of the Head, lateral 

 flexion of the fetal head toward the mother's sacral 

 bone, the left ear approaching the left shoulder, and 

 the right parietal bone presenting in a left occipito- 

 anterior position. It is the third step in the mechan- 

 ism of delivery. See Obliquity. N.'s Rule, for 

 predicting the date of confinement : " Count back 

 three months from the date of cessation of the last men- 

 strual flow, and add seven days." Hirst modifies this 

 by counting from the date of appearance, believing 

 that the result will be more accurate. N.'s Pelvis. 

 See Pelvis, Female, Deformities of. N.'s Theory. 

 See Heredity. 



Naevoid ine' -void). See Nevoid. 



Naevose yne'-vos). See Nevose. 



Ncevus (ne'-vus). See Nevus. 



Nail {mil) [ME., naile, a nail]. The horny lamina cov- 

 ering the dorsal aspect of the end of each finger and toe. 

 N.-area, a thickening of the epitrichium over the end 

 of the digit, marked out quite definitely by a limiting 

 groove that persists more or less distinctly through- 

 out life. It first appears in the human embryo about 

 the beginning of the third month. N.-bed, the de- 

 pression in which the nail rests. N.-bone, the lacry- 



mal bone or os unguis. N. -brush, a hand brush for 

 cleaning the finger-nails. N. -culture, a term applied 

 in bacteriology to a stab-culture showing a growth 

 along the needle-track, and en the surface a button-like 

 projection, giving the appearance of a nail driven into 

 the gelatin. N.-file, a small single-cut file for trim- 

 ming the finger-nails. N.-fold, the portion of epi- 



Ungual Extremity of 

 Finger, showing Nail. 



. Fold of skin covering root 

 of nail. 2. Incised and 

 turned back. 3. Semilunar 

 portion of subungual skin. 

 4. Portion corresponding to 

 body of nail. 



Concave Aspect of 



1. Its proximal border. : 

 Portion corresponding t 

 lunula. 3. Body. 4. Frc 

 distal border. 



1106 2 7 3 H 



Longitudinal Section 

 Ungual Extremity 

 Finger, showing Nail. 



:. Corneous layer of epider 

 mis of dorsal aspect. 2, Re 

 flection of this la\ 

 nail. 3. Superficial layer o: 

 nail. 4. Corneous 

 epiderm of pulp of finger 

 5. Rete Malpignii ofdorsa 

 aspect. 6. Refleetii 

 layer. 7. Second retl 

 8. Rete Malpighii ol 

 finger. 9. Derma ol 

 aspect. 10. RenY 

 derma, n. Second 

 tion of derma. 1. 

 of palmar aspect of finger 

 13. Ungual phalanx. 



dermis that covers the root and edges of the nail. N. 

 groove, the depression for the insertion of the nai 

 N., Hang, a little shred of skin hanging from th 

 finger at the side of the nail. Hang-nails are som< 

 times quite painful, and the little wounds offer <> 

 trance to septic matter. N., Infleshed, Ingrow 

 ing, or Ingrown, an overlapping of the nail by th 

 flesh, from pressure, attended with ulceration. N- 

 matrix, the proximal end of the N.-bed ; the strw 

 ture from which the nail grows. N.-pad. The »o 

 as N. -rampart. N. -plate, the volar side ol 

 N. -rampart, the epidermic border against which th 

 margin of the nail rests. N., Reedy, N., Striate* 

 a nail presenting longitudinal furrows. N.-root, li 

 portion of the nai: attached to the X. -matrix. N 

 Spring. Same as Hang-nail. N., Turtle-back, ' 



