256 



Discovery of Poison Organs in Fishes. 



this axillary sac after discovering in another genus of fishes 

 a poison-organ which structurally is identical with and as 

 complete as that of the venomous snakes. This fish belongs 

 to the family Batrachidce, and a single species of the genus 

 has already been described in the Museum catalogue of 

 fishes, part hi. page 174, under the name Thalassophryne 

 maculata. Being a very small species, Dr. Giinther did not 

 discover the apertures in the spines, although really exist- 

 ing. A second species having been recently brought over 

 with a collection of fishes from Guatemala by Messrs. Salvin 

 and Godnian, which has been named Thalassophryne reticulata, 

 being ten and a-half inches long, the structure of these spines 

 was more easily discovered. 



This fish is armed with a single sharp spine upon each* 

 opercular bone, and two upon the dorsal fin eight lines in 

 length. Each spine has an aperture on its anterior surface 

 just below the apex, and upon pressing back the integu- 

 ment in which it is enveloped nearly to its summit, a thick 

 creamy fluid flowed or spirted from the aperture. Upon 

 removing the integument with a dissecting knife a small 

 sac or reservoir was exposed, attached to the opercular 



THALABSOFURTNB BKTICULATA. 



a a, The opercular spines, h I, The dorsal spines. B d, Opening in poison sac. 

 c c, The mucous canals. 



bono near its base, which contained tho same creamy fluid 

 which had previously been seen to exude from the aper- 

 turo near its apex. On inserting a bristle into tins, aperture it 

 reappeared at another opening near the base of tho spine, and 

 within tho sac or reservoir already described. A tube leading 

 from this reservoir was also detected, having a free end lying 

 within the sac, and evidently being the canal by which the fluid 

 was conveyed bo tin's receptacle. There seems no doubt that 

 this canal goes directly into a branch of the mucous system of 



