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XXIV. On the structure of the poisonous fangs of serpents. By 
Thomas Smith, Esq. F. R. S. 
Read June 4, 1818. 
Wh en the poisonous fangs of serpents are attentively 
examined, a slit or suture may be observed extending along 
the convex side, from the foramen at the base to the aperture 
near the point. (Plate XXII. A. B. C. D.) This is a conse- 
quence of an unusual, and hitherto, I believe, entirely unno- 
ticed structure, resulting from the mode of formation of the 
tube through which the poison flows. 
My attention was called to this structure, by having lately 
received from my friend Mr. Herbert Ryder, the assay 
master to the mint at Madras, the bones of the skull of a 
cobra de capello. I had some years since noticed the slit 
running along the convex side of the fang, in making a 
preparation of the head of the common viper of this country, 
in which it is distinctly seen W'hen magnified ; nevertheless, it 
seems to have been overlooked by all the numerous authors 
who have written upon the subject of the venomous fangs of 
the viper, and who, as far as structure is concerned, do not 
appear to have advanced beyond Pliny, to whom, and even 
anterior to whose time, the circumstance of their being 
tubular was well known. 
All teeth being formed from a pulp, which has the shape 
that the tooth itself is destined to retain, it has probably been 
imagined that the tube of the poisonous fangs of serpents 
