64 VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 



The nuclear and the cytoplasmic elaborations constitute two distinct 

 cytes of secretion. The nuclear elaboration is to furnish the cytoplasma 

 with necessary material for the proper secretory work, while the cytoplasmic 

 cyte is an elaboration, in which not only the basal protoplasma takes part, 

 but also throughout the entire cell, especially the perinuclear cytoplasma. 



The venogene grain can be distinguished from the venom grain by its 

 affinity to Unna's blue, safranin, and fuchsin. The venom grain is eosino- 

 philic. It is never secreted in granular form, but always after the intracellu- 

 lar dissolution. In the lumen of the glandular .tubules no venogene grain 

 is to be found. 



DYNAMICS OF THE FUNCTION OF POISON APPARATUS. 



(Plates 21 and 22.) 



The bones which are concerned with the insertion of the poison fang into 

 the victim can be divided into direct and indirect. The direct bone is the 

 supramaxillary, to which the fang firmly ankyloses on the alveolar socket. 

 The supramaxilla is a sort of triangular body and has four facets. The under 

 surface presents a somewhat dull triangle, or rather a pentagonalum, with its 

 apex directed forwards. Here near the apex two sockets are found, in which 

 two acting fangs are usually implanted. The anterior external facet has an 

 irregular surface, and in the crotaline snakes this is eclipsed at the posterior 

 external portion by a spherical excavation — a fossa characteristic of the 

 "pit" vipers. The anterior internal surface is very smooth and oblong. 

 The posterior surface is defective by the presence of a spherical depression, 

 which at the same time excavates the upper half of the anterior external 

 facet. In the posterior surface, just above the fossa, is a smooth articulat- 

 ing surface, which connects this bone with the corresponding articulating 

 surface of the prefrontal (lachrymal) bone. 



Near the internal edge of the posterior surface is a small, deep furrow, at 

 the bottom of which are two holes, one communicating with the spherical exca- 

 vation-pit and the other with the bottom of the alveolar sockets of fangs on the 

 under facet. The border where the under and posterior facets meet forms an- 

 other articulating line — a narrow, straight line — and is connected with the 

 thin, extended end of the ectopterygoid bone (transversum) by a strong hori- 

 zontal ligament. This maxillo-ectopterygoid articulation is freely mobile and 

 is one of the most important factors in erecting the fang. The maxillo- 

 prefrontal articulation is also of such nature that the maxillary bone is easily 

 rotated and erected. The denomination of different surfaces of the maxillary 

 bone is naturally variable with the positions to which this bone may event- 

 ually change, but by the under "surface" is always meant the facet where 

 the dental alveolar sockets are present. This "under surface" becomes the 

 "posterior" when the fangs are horizontally folded with their points directed 

 backwards, and the "posterior surface" will then turn to the "upper." 



1 A minute description of the osteology, myology, and the physiological mechanism of the bite of the 

 Crotalus is given by S. Weir Mitchell, Researches upon the venom of the rattlesnake, Smith- 

 sonian Contributions to Knowledge, 1861, Washington, D. C. 



