From a comparative study of physiology of nerves of hearts of principal 

 groups of mollusks and arthropods, pteropods excepted, the author con- 

 cluded that invertebrates possess, probably without exception, excitor or 

 inhibitor nerves, and usually both. This contradicts the earlier view 

 that the heart of many mollusks is entirely free of nervous tissue. - J.L.M. 



258 



Carlson, A. J. 1906. 



Comparative physiology of the invertebrate heart. V. The heart rhythm under 

 normal and experimental conditions. Am. J. Physiol. 16(1) : 47-66. 



259 



Carlson, A. J. 1906. 



Comparative physiology of the invertebrate heart. VI. The excitability of 

 the heart during the different phases of the heart beat. Am. J. Physiol. 

 16 (1) : 67-84. 



260 



Carlson, A. J. 1906. 



Comparative physiology of the invertebrate heart. VII. The relation between 

 the intensity of the stimulus and the magnitude of the contraction. Am. J. 

 Physiol. 16 (1) : 85-99 . 



261 



Carlson, A. J. 1906. 



Comparative physiology of the invertebrate heart. VIII. The inhibitory 

 effects of the single induced shock. Am. J. Physiol. 16(1) : 100-109. 



262 



Carlson, A. J. 1922. 



A note on the action of curare, atropine, and nicotine on the invertebrate 

 heart. J. Gen. Physiol. 4(5): 559-568. 



The primary action of curare and nicotine in mollusks is on the central 

 nervous system and peripheral ganglia and not on motor nerve endings in 

 muscle. Action on nerve centers is a primary stimulation followed by 

 temporary or permanent paralysis depending on strength of dose. Atropine 

 did not paralyze motor nerve endings in muscle in any mollusk studied. 

 Solutions of curare, atropine, and nicotine of sufficient concentration to 

 affect the heart appreciably have a primary stimulating action. The author 

 concludes that the primary action is on ganglion cells of the heart and not 

 on muscle. Continued action of solutions of the 3 alkaloids on heart of 

 mollusks abolishes the influence of inhibitory nerves on the heart. In 

 Venus, curare may act for 20 to 30 min before action of inhibitory nerves 

 is abolished. Venus (species not given) was one of 22 mollusks studied, 

 but no details are given other than the single mention cited above. - J.L.M. 



263 



Carlson, Gary P. 1972. 



Detoxification of foreign organic compounds by the quahaug, Mercenaria 

 mevaenavia. Comp. Biochem. Physiol. 43B: 295-302. 



Hard clam hepatopancreas was unable to metabolize the insecticide EPN, 

 O-demethylate p-nitroanisole, N-demethylate aminopyrine, or oxidize hexo- 

 barbital. Quahaug hepatopancreas was able to reduce p-nitrobenzoic acid 

 to p-aminobenzoic acid. The reaction was maximal at 35-45°C and pH 6.0, 

 was stimulated by flavins, and inhibited by potassium cyanide but not by 

 SKF-525A or carbon' monoxide . Nitroreductase activity was found to a lesser 

 extent in mantle, gill, foot, and gonadal tissue. - Modified auth. abstr. 

 - J.L.M. 



70 



