164 Mr. G. J. Allman on the Sting 
From the posterior edge of the operculum the integument 
is continued over the spine to within a very short distance of 
the point; by which means the spine is inclosed in a com- 
plete sheath for nearly its entire length, and the groove at 
each side is converted into a perfect tube, extending from the 
conical cavity at the base almost to the point of the spine. 
The result of this arrangement, is a structure beautifully 
adapted for the conveyance of a fluid from the base to the 
apex of the spine. 
The spines of the dorsal fin are also grooved, but the grooves 
disappear towards the base, after becoming superficial, and do 
not terminate in cavities similar to those at the bases of the 
spines of the opercula. | : 
I have not as yet been able to detect any specific gland 
connected with this apparatus. There is, indeed, in the bottom 
of each of the conical cavities above-mentioned, a small pulpy 
mass, which may possibly be of a glandular nature; but in 
ascribing to it the property of secreting the virus, I do nothing 
more than hazard a distant conjecture. It seems, indeed, to be 
chiefly composed of fatty matter ; and on puncturing my hand 
with a lancet and introducing a little of this substance taken 
from a fish which had been about twenty-four hours dead, no 
phenomena of any interest were the result, there being merely 
a slight smarting produced, such as might be expected from 
the introduction of any such extraneous matter into a recent 
wound, and very different indeed from the intense pain pro- 
duced by the sting of the living fish. The property of secre- 
ting the virus may probably with more truth be ascribed to 
