AF 51.1 ACCESSORY FIXATIVE FORMULAS 205 



AF 50 Narcotizing Agents 



Narcotizing agents as here given are not intended for use on animals wliicli will subse- 

 quently recover, but are intended to leave in a relaxed condition small invertebrates and 

 larvas which are subsequently to ho fixed. It is hoped by the worker that these relaxed speci- 

 mens will not contract out of their normal shape on the application of fixative. One of the 

 best methods of narcotizing small marine invertebrates is with the aid of carbon dioxide, for 

 manj^ of these forms have a natural resi)onsc of endcavoritig to increase tlu;ir surface area 

 when they hnd their oxygen supjily being diminished or the concentration of carbon dioxide 

 in their environment rising. Carbon dioxide is best used for this purpose by taking one of the 

 devices commercially sold for aerating drinks, filling it with sea water, and saturating thi.s 

 with carbon dioxide. In some fresh-water invertebrates heat will produce the same effect. 



Many poisons have from time to time been regarded as narcotics and thus Zebrowski 1926 

 (21400a, 45:258) has recommended a 2% solution of strychnine sulfate for planaria; this 

 same reagent was recommended for rotifers by Pritchard 1851, 39. Magnesium sulfate is 

 widely used for marine coelenterates, since an excess of magnesium ions in the water appar- 

 ently has the effect of inhibiting muscular contraction in these forms. 



Either ether or chloroform may be used in the vapor phase by the process of exposing small 

 invertebrates swimming under a coverslip to an atmosphere of a volatile anesthetic. This 

 process was first recommended by Beauchamp 1904 (5401, 29:26) who used it for Vorticella 

 and other stalked ciliates. In the experience of the writer cocaine, or cocaine hydrochloride, is 

 still, in spite of the flood of synthetic substitutes, the best narcotic for general use. 



AF 51.1 Formulas 



51.1 Baker test. 1937 Gatenby and Painter Gatenby and Painter 1937, 10 



formula: water 90, 90% ale. 10, cocaine hydrochloride 0.6 



51.1 Bujor 1901 1915, 10:49 



formula: water 100, sodium chloride 0.9, ether 10, 40% formaldehyde 10 

 RECOMMENDED FOR: anesthetizing and killing cestodes before regular fixation. 



61.1 Cori 1893 23632,55:626 



formula: water 90, methanol 10, chloroform 0.3, sodium chloride 0.6 



51.1 Gray 1935 Micr. Rec. (1935) 35 



REAGENTS required: A. Rousselet 1895 AF 51.1; B. 3% hydrogen peroxide 10, water 90 

 method: [stalked ciliate protozoa] -^ A, added drop by drop, till cilia start slowing —> B, 

 added drop by drop till cilia stop — > fixative, instantly 



51.1 Gray 1952 Gray 1952, 14 



formula: menthol 48, chloral hydrate 52 

 preparation: Grind in a mortar until an oily fluid results. 

 method: Place a few drops on the surface of water containing animals to be narcotized. 



51.1 Hanley 1949 Microscope, 7:156 



formula: water 90, ethylene glycol monoethyl ether 10, eucaine hydrochloride 0.3 



51.1 Langeron 1942 Langeron 1942, 1013 



formula: water 50, methanol 50, cocaine hydrochloride 5 



note: This is called "concentrated liquid of Rousselet" by Langeron. See, however, 

 AF 51.1 Rousselet 1895. 



51.1 Lo Bianco test. 1937 Gatenby and Cowdry Gatenby and Cowdry, 1937, 11 



formula: sea water 40, water 10, 95% ale. 30, glycerol 20 



51.1 Morrison 1948a Turtox News, 26 :5i 



formula: water 93, methanol 7, cocaine hydrochloride 0.03 



51.1 Morrison 1948b Turtox News, 26 :5i 



formula: water 70, 95% ale. 7, methanol 5, hydroxylamine hydrochloride 0.1 



