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1. In the dark adapted Mnemiopsis, mechanical stimulation causes luminescence along the eight rows of paddle plates. The tactile receptors for this reaction lie only in the paddle plate rows, and are connected only longitudinally along these rows. 2. The tactile receptors for ciliary and muscular movement are distributed generally over the surface and are connected by a nerve net. 3. Luminescence may occur at 3°C. provided the animal has been kept sufficiently long at that temperature. Ciliary action goes on at – 0.6°C. 4. Luminescent paper made by spreading the luminescent secretion of Mnemiopsis on filter paper, yields the following effects. The paper shows luminescence in solutions of K2SO4, KCl, MgSO4, SrCl2, CaCl2; no luminescence in NaCl, MgCl2. Changes in pH value of salt solutions between pH 6 and 8 do not affect the phenomenon. Illumination of the paper with strong light for longer time than necessary to suppress luminescence in the living animal has no effect on the subsequent luminescence of the paper. Hence in the animal, light affects luminescence through the photoreceptor system; the nervous system carries the impulse to the luminescent organs. 5. The power of luminescence of the animal is suppressed by sufficiently intense light, the relation between the intensity and the time requisite being expressed by the equation for the Bunsen-Roscoe photochemical law, namely, I · t = K. 6. It is suggested that the reaction scheme involved in luminescence is of the following form See PDF for Equation in which A is the luminescent substance in the resting, dark adapted animal, L is the light-giving decomposition product, and D is a product which does not yield light. 7. The luminescent substance receives double innervation and the character of the decomposition is determined by the type of nerve fiber stimulated.

The sensitized luminescence of naphthacene embedded into 1,2,5,6-dibenzanthracene crystals has been investigated on different substrates. Since the fluorescence intensity of the energy donor and the energy acceptor is proportional to the quantity of the components, they can be determined with high accuracy. On Whatman 1 filter paper, 10 -10 M/l naphthacene (i.e. the absolute quantity of 10 -13 g) and 5 × 10 -5 M/l of 1,2,5,6-dibenzanthracene (that is, 10 -7 g) have been determined. The experimental results of the quantitative analysis clearly display the delayed fluorescence of the system.

The effect of disulfide bonds on the phosphorescence properties of tyrosyl residues of model compounds and ribonuclease A was investigated. 1. 1.|The tyrosyl residues of polytyrosine, insulin heptapeptide, lysine-tyrosine copolymer, and cysteinyltyrosine are characterized by luminescence ratios ( q P q F ) which are close to 1. The phosphorescence emission decays in an exponential manner with phosphorescence lifetimes (τP) fluctuating between 2.3 and 2.6 sec. 2. 2.|The cystinyl-bis-tyrosine peptide exhibits an abnormal behavior in its luminescence properties when compared to free tyrosine. Its luminescence ratio ( q P q F ) is equal to 0.2 and its decay time (τP = 0.2 sec) is shorter than the value of free tyrosine. 3. 3.|Ribonuclease A is characterized by a luminescence ratio of 0.58 and by a phosphorescence decay time of 1.4 sec. Reductive cleavage of the disulfide bonds brings about an increase in the phosphorescence yield ( q P q F = I ) and phosphorescence decay time (τP = 2.3 sec). The low phosphorescence yield of ribonuclease A is related to a quenching effect exerted by the disulfide bonds on the triplet excited state of tyrosyl residues.

1. 1. Porichthys luciferin gives an extensive series of luminescent cross-reactions with the luciferases of various other luminous organisms. 2. 2. The luminescence reaction of Porichthys is very similar to that of the marine ostracod crustacean, Cypridina hilgendorfii. 3. 3. A relatively high percentage of the stomachs of adult Porichthys contained the euphausiid, Euphausia pacifica. 4. 4. Theories regarding the origin of luciferin in Porichthys and some other shallow-water fishes are discussed. 5. 5. The discovery of luminescence in the marine teleosts, Apogon poecilopterus and Parapriacanthus dispar, is reported.

Out of three different types of aromatic isothiocyanates tested, 1-naphthylisothiocyanate is the most suitable for stepwise degradation of proteins. The hydantoins formed exhibit good chromatographic properties on paper (solvents: 5% acetic acid; 10% pyridine; phosphate buffer, pH 6, μ 0.1) and on electrophoresis (pyridineacetate buffer). The pH dependence of the emitted fluorescence, which differs for individual amino acids, is of great diagnostic value. The sensitivity is due to the luminescent properties of these derivatives being increased up to the order 10 −3 to 10 −4 μmoles, which is comparable to the sensitivity of the 1-dimethylamino-5-naphthalene sulphochloride (DANSYL) derivatives.