PLATE XXII. 



Figs. 18, 19, 20. Stages in replacement of small poison gland (p.gl.) by 

 mucous glands (m.gl.) from sides of tail. Mucous nuclei dark. 

 Secretion (sec.) shown in poison part only. Benda's iron- 

 haematoxylin. > 342 



Figs. 21, '22, 23, 24. Tangential sections of poison glands, showing nerve 

 endings (ii.e.) on nuclei of poison cells (nuc.p.c.). Mallory's 

 conn, tissue stain. Figs. 21, 22, 24. X 1850. Fig. 23. X 875 



Figs. 25 and 26. Tangential section of wall of poison glands, showing nerve 

 endings (n.e.) on muscles (./.) Fig. 25, Mallory's conn, 

 tissue stain. Fig. 26, Cajal's silver nitrate-pyrogallic acid. 



XH75 



[2661 



