PLATE XVIII, 



FIG. 137. 



Capillary circulation in a portion of the web of a Frog's foot. 

 FIG. 138. FIG. 139 



Alterations in form in blood-discs : 1, Stellate or mul- 

 berry form; 2, On warm stage; 3, Amoeboid white-cell 

 forms. 



FIG. 140. 



Blood-discs : 1, Eliptic Discs of Amphibia ; 

 2, Human red-corpuscles ; 3,White or lymph- 

 corpuscle; 4, Rouleaux of red-discs. 



FIG. 141. 



Pus-corpuscles: o, with acetic acid. 

 FIG. 142. 



Mucous corpuscles and epithelium. 



Varieties of Epithelium ; a, Tessalated ; 6, Squamous; 

 c, Glandular; d, Columnar ; e, Ciliated. 



