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, Scorpena, and Synanceia. 
This fact suggested to Dissard and Noë? 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 1s 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 hæmatosis. 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 itis seized, and that Scorpæna and Synanceia like- 
1“ Les poissons vénéneux,” Paris, 1900. 
2“ Sédentarité des poissons venimeux,’’ Comptes rendus de la Société de 
Biologie, 1895, p. 86. 
19 
