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, 'S-\. 24. — Tangential sections of poison glands, showing nerve 

 endings (».<.) on nuclei of poison cells {nue.p.c). Mallory's 



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



Figs. 2.1 and 2G. — Tangential section of wall of poison glands, showing nerve 

 endings [n.e.) on muscles (m.f.). Fig. 25, Mallory's conn, 

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

 875 



