Cells 



f I. Fixed 



THE CONNECTIVE TISSUES 87 



[ (a) Ordinary connective-tissues cells. 



(b) Plasma cells. 



(c) Mast cells. 



(d) Clasmatocytes 



2. Wandering. 



Intercellular substance 



[ . V „., I white or fibrillated, 



(a) Fibres i ,, , ,. 



I [ yellow or elastic. 



(b) Ground or basement substance. 



r 



m- 



r. 



Fig. 30. — Mucous Connective Tissue from Umbilical Cord of Eight-inch Foetal 

 Pig. X600. At this stage the ground substance shows some fibrillation. 



Connective -tissue Cells. — (a) The ordinary fixed connective- 

 tissue cell is often the only connective-tissue cell seen in ordinary 

 sections. It is an irregular shaped cell, often quite flattened 

 with clear or slightly granular cytoplasm and an oval nucleus. 

 (Figs. 31 and 32,) In loosely arranged tissue where the cells are 

 well separated, the cell is usually stellate with many branches, 

 which anastomose with branches of neighboring cells. In a dense 

 tissue such as the cornea, these cells apparently lie in little cell 

 spaces or lacunae from which minute channels (canaliculi) extend 

 in all directions to unite with canaliculi from adjoining spaces (^Fig. 

 33). Delicate cell processes extend into the canaliculi and there 

 anastomose with processes from other cells thus forming a sort of 

 syncytium (Fig. 34). Owing to the extreme sensitiveness of the 

 protoplasm of the connective-tissue cell to most fixatives, its usual 



