1864. ] DR. A. GUNTHER ON A POISONOUS FISH. 155 
4. On a Porson-orGAN IN A Genus or Batracuorp Fisues. 
By Dr. ALzert Ginruer. 
Many fishes are known which, provided with long, bony, and 
Sometimes serrated spines, are justly feared on account of the 
dangerous wounds they inflict. The Sting-Rays, many Siluroids, and 
some scaly fishes, like the Weevers, are thus armed, Although the 
effects ascribed to such wounds have doubtless been exaggerated in 
many cases, natives and fishermen, as well as travellers, agree in the 
belief that some poison must be communicated. However, with the 
exception of a single instance, viz. that of the Weevers*, compara- 
tive anatomists have never pointed out a trace of an organ secreting 
or conducting a poisonous substance ; and consequently the poisonous 
nature of the wound has been doubted, the worst cases being ex- 
plained by the mechanical effect of a serrated spine, by the influence 
of the climate, or by the peculiarity of the constitution. Thus in 
all the hand-books of comparative anatomy the presence of a poison- 
organ in the class of fishes is denied, and even Bleeker + (than whom 
no naturalist has had better opportunities of observing such fishes 
during life) expressly says that they were unjustly reputed poisonous. 
On the other hand, I have heard of so many positive facts from 
highly educated travellers and excellent observers (some of whom, 
being medical men, had treated cases of this nature), that it appeared 
to me necessary to give every attention to this subject. Especially 
it seemed probable that a sac with a more or less wide opening in 
the axil of the pectoral fin of many Siluroid and of some other fishes 
would contain a fluid which might be introduced into a wound by 
means of the pectoral spine, which would be covered with it, like the 
barbed arrow-head of a bushman. 
Whether this secretion is equally poisonous in all the Species 
which are provided with that axillary sac is a question which can 
only be decided by experiments made in the tropics ; but I can hardly 
doubt its poisonous nature, after discovering in a genus of fish a 
poison-organ which structurally is the same as in the venomous 
* Dr. J. E. Gray has directed my attention to a paper by Mr. Byerley, con- 
tained in the Proceedings of the Literary and Philosophical Society of Liverpool, 
No. 5, 1849, p. 156. In this paper Mr. Byerley demonstrates, in the most 
convincing manner, that the double-grooved opercular and dorsal spines of the 
Weevers are poison-organs. Although the structure of the spines, with their 
external grooves, were known to previous writers, it is Mr. Byerley’s merit to have 
shown the presence of a cavity within the substance of the spines which is the 
proper depository of the poison before its ejection. But, at present, I cannot 
agree with him that the body found in the cavity and in the groove is a gland ; 
it appears to me that what he considered to be a gland was the poisonous fluid 
itself, coagulated and hardened by the action of the spirits in which the speci- 
mens had been immersed in order to render “ the gland more opaque and denser.” 
I formed this opinion from examinations of specimens of Z'rachinus draco 
as well as of TZ. vipera, which, however, had been in spirits for a considerable 
period. Nevertheless there is no doubt that the poison-apparatus of Tyachinus 
is homologous with that of Thalassophryne, only in the latter it is developed to 
as great a perfection as in the fang of a viper. 
Tt Atl. Ichthyol. Silur. p. 21. 
