MICROSCOPIC OBJECTS. 27 



Fig. 53. Starch from Rice (Oryza sativa), x 450. 



The starch-granules of Rice, like those in the preceding 

 drawing of the Oat-starch, are massed together in a conglo- 

 merate form; but in this instance the granules are more 

 irregular in shape,, and also greatly pointed, which character- 

 istic gives the peculiar gritty feel to Rice-starch. 



The presence of this, or any other kind of starch, may be 

 distinguished in any article adulterated with it, by the iodine 

 test, which is this : On placing a small quantity of mustard 

 (we will say for instance) under the microscope and adding 

 a small drop of the tincture of iodine to it, if starch in any 

 form is present a number of dark blue or black grains will 

 be seen ; these are the starch-granules, which have been so 

 coloured by the iodine. 



Fig. 54. Starch from. Maize (Zea Mays), x 350. 



These granules are taken from the centre of the Indian 

 corn, or Maize as it is generally called. The form is slightly 

 different from that of the granules which are found in the 

 outer part of the grain, which assume more of the hexagonal 

 form, together with a near resemblance to that of cellular 

 tissue, both of which appearances are caused by the pressure 

 of the entire mass upon each individual granule. 



This and all the other starches show their structure best 

 when mounted in liquid. 



