GLOSSARY 269 



mEQ: Milli-equivalents or equivalent weight in grammes x 10"^ 



mg: Milligramme. 



micro-EQ: Micro-equivalents or equivalent weight in grammes 



X 10-«. 

 *MIH: Moult-in hibiting hormone of Crustacea, released from sinus 



gland, 

 ml: Millilitre or cubic centimetre. 



mm Hg: A measure of pressure in millimetres of mercury, 

 m.n.c. : Median neurosecretory cells in insect brain. 

 Molar : A solution of a substance containing its molecular weight in 



grammes per litre. 

 *MPH: Moult-promoting hormone of Arthropoda (=*ecdysone of 



Insecta). Sources in antennary or maxillary glands. 

 *MSH: Melanophore-stimulating hormone or *B, dispersing black 



pigment in cold-blooded vertebrates; secreted from pars inter- 

 media of adenohypophysis. 

 MTU: Methylthiouracil. 

 N: Nitrogen. Also used for a "normal" solution of any chemical 



substance containing its equivalent weight in grammes, dissolved 



in one litre of water. 

 Na+ : Sodium ion (cation). 

 NaCl: Sodium chloride. 

 NaHCOg: Sodium bicarbonate. 

 Nephrectomy : Operative removal of the kidneys. 

 Ogi Oxygen molecule. 



P : Phosphorus, the characteristic element in phosphates. 

 *PDH: Palaemo7ietes-d2ir\itnmg hormone, dispersing red pigment in 



chromatophores of Crustacea (Decapoda, Natantia). Source 



uncertain, but can be extracted from C.N.S. 

 Peristalsis: rhythmic contraction of longitudinal muscles, e.g. for 



driving the contents along the intestine. 

 pH: Hydrogen ion concentration (=negative logarithm; e.g. 10~'N 



ions is given as pH 7.0). 

 Pitocin : A commercial extract of the posterior lobe of the mammalian 



pituitary body containing mainly * oxytocin. 

 Pitressin : A commercial extract of the posterior lobe of the pituitary 



body, containing chiefly the "pressor" fraction, or *ADH. 

 Pituitrin: A commercial extract of the posterior lobe of the mam- 

 malian pituitary body (i.e. of the neurohypophysis) containing 



^oxytocin and *ADH. 



