HOT STAGE. CONNECTIVE TISSUE. 



33 



and set the flame of the bunsen burner under this part. Guard against 

 over-heating by periodically testing the plate between the stage and 

 flame with your finger. 



The ciliary movement quickens. If the temperature be 

 sufficiently elevated the motion will cease (heat stiffening}. 



Fu;. 13. Hot stage. A plate of tin insulated from the stage of the microscope 

 by a piece of blotting paper B, S the slide through which is seen the central 

 opening in the stage, H line along which the plate is bent up ; the flame is placed 

 under this end. 



Secreting Epithelium. See digestive tract. 



Connective tissue proper. Areolar tissue. Spread a small piece 

 of the subcutaneous tissue of a mammal (rabbit or rat), by means of 

 needles, on a dry slide, into as thin a film as possible (sem'i desiccation), 

 breathing upon the tissue from time to time to obviate drying. Moisten 

 with normal saline and cover. 



Recognise the following : (a) White fibres, transparent wavy 

 bundles exhibiting delicate longitudinal markings, (b) Elastic 

 fibres, fine straight filaments, some of great tenuity with 

 distinct though infrequent branchings, broken ends tend to 

 curl up into irregular coils. Their higher refractive index 

 gives them a sharp outline when in focus. (c) Connective 

 tissue corpuscles, difficult to detect in the rabbit, more easily 

 seen in the rat and guinea pig. 



^Effect of acetic acid. Irrigate with 1 P- C - solution. 



Observe that the white fibres are rendered more transparent 

 and that they swell. Constrictions may be made out in places 

 where a ring-like filament encircles a fibre. The elastic fibres 

 now appear distinct, and the corpuscles or at least their nuclei 

 become evident. 



6 



