VENOMS IN THE ANIMAL SERIES 289 



is generally found in one or more special glands, situate at the 

 base of the dorsal or caudal fins, or beneath the opercular spines. 

 When the animal defends itself it inflicts wounds with these rays, 

 and ejects from its poison-glands a toxic or irritant liquid, which 

 enters the sores. 



The flesh of these fishes is not usually poisonous, whereas a 

 fairly large number of other species, which do not inflict wounds, 

 cause intoxicating effects when eaten. These latter do not come 

 within the scope of this work ; but the reader who may desire to 

 obtain information with regard to them will find them well described 

 in J. Pellegrin's memoir,' in that by Dupont, and especially in the 

 papers of A. Corre. 



Venomous fishes almost all belong to sedentary species, as in the 

 case of the genera Trachinus, Cottus, Scorpcsna, and Synanceia. 

 This fact suggested to Dissard and Noe ^ a very hazardous theory 

 in order to explain the existence of a poison-apparatus in these 

 animals. The venomous fishes being sedentary, say these authors, 

 have no need of a poison-apparatus ; their prey offers itself to them 

 without effort on their part, and, on the other hand, they escape 

 destruction by their enemies. If, therefore, they possess a poison- 

 apparatus it is because the conditions under which they live entail 

 the lowest value for the co-efficient of respiration, diminish the 

 quantity of the ambient radiations and the oxygenation of the 

 medium, and lead to diminished hsematosis. For these reasons the 

 activity of anaerobic life becomes greater, and the formation of 

 venoms takes place. 



This theory, derived from the conceptions of A. Gautier with re- 

 gard to the formation of toxic leucomaines, appears scarcely tenable, 

 for it is evident that the weever, for example, erects its first dorsal 

 spine as soon as it is seized, and that Scorpcena and Synanceia like- 



' " Les poissons veneneux," Paris, 1900. 



^ " Sedentarite des poissons venimeux,'' Comptes rendus de la Societe de 

 Biologie, 1895, p. 86. 

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