POISON-GLAND OF THE COBRA. 19 



bands , three of them belong to one lobe , and the three others 

 to a second lobe. The granulated bands farthest off are 

 adjacent to their respective poison lakes. 



If the cells of the glandular epithelium be examined in 

 their normal state of secretion under high power the foUowing 

 structure may be determined. 



The cells of the glandular epithelium (fig. 3) are regularly 

 prismatic (they are, therefore, in longitudinal sections rectan- 

 gular). They are about 30 [k in height and contain near the 

 base a deeply stained nucleus from 7 to 8 [a. in width. 



The cytoplasm is particularly interesting to examine in 

 sections fixed mth Regaud's liquid, for one can then see the 

 mitochondrial substance. This substance is considered to-day 

 as the most active portion of all the cytoplasm, for it plays the 

 chief part in the elaboration of the products of the secretion. 



Li the cells shown in fig. 3 several zones may be recognized 

 in the cytoplasm : (I) at the base of some cells below the nucleus 

 a quantity of very fine granulations (mitochondrise) can be 

 seen, and in others small filaments (chondriocontes) ; (2) at 

 the sides of the nucleus the masses of granulations seem to 

 continue into a kind of chain of beads (chondxiomites) which 

 generally run along the lateral walls of the cell ; (3) above the . 

 nucleus a cytoplasmatic space is found free from granulations ; 

 (4) at the free end of the cell are granules far more voluminous 

 than the mitochondrise (their breadth can reach to 2 or 3 [->.). 

 These are what Launoy* calls " Venogen's granules." In 

 other cells one sees alongside the granules, plainly coloured 

 by the irouized hematoxylin, smaU spaces, the same size as 

 the granules, from which the stained contents have disappeared. 



It seems, therefore, obvious on examining these sections that 

 the mitochondrial substance, which is in direct relation with 

 the secretion of the granules, plaj^s in their fabrication a role at 

 least as important as that which Launoy ascribes to the nucleus. 



The granules we have seen are situated at the free extremity of 

 the cell, in contact with the cavity of the gland. Gradually 

 they unite with each other and then finally escape, and together 



* Launoy, L., Contribution a I'etude des phenomenes nucl^aires 

 de la secretion (Cellules a venin — Cellules a enzyme). Ann. des Sc. 

 Nat. T. 18 (Zool.), 1903. 



