117 



Examine each portion of tissue separated out, and 

 remove to a fresh clear drop of salt solution. 



Remember that in examining under the 

 microscope the apparent right hand is really the 

 left, and vice versa. 



This method, which is longer than Method i, 

 requires more dissection and teasing out in order 

 to isolate the glands cleanly, and, as we have 

 said, may still be followed, even if No. i has 

 failed ; but our experience has been that Method i 

 is learned at once without any difficulty. 



imi.us •/■ 



^ •fellL 



Fig. 36. Microscopic Structure of Salivary Acinus and that of 

 a Newly-Hatched Mosquito (right) 



Ascertain that the glands of either side 

 consist of three acini, the ducts of which join 

 almost immediately after leaving the acinus to 

 form a single long duct. 



1. Observe that of the three glands of each 

 side (Figs. 35 and 38) :— 



(i) Two are highly refractile, and the cells 

 in these are very distinct and clearly defined 

 (lateral glands). 



(ii) One is much less refractile, and the 

 component cells are much less easily defined 

 (central gland). 



2. Observe that each acinus has a duct 



