66 



BACTERIOLOGICAL METHODS 



As already indicated the number of organisms in food sub- 

 stances is in direct ratio to the following conditions : 



1 . Insufficient culling of partially and wholly decomposed fruits. 



2. Unsanitary factory conditions and unsuitable methods. 



mmma&^&m 



Ova of the Parasitic Worms or Man 

 TREMATODA 



ft A W N TO SCALE X ICOO 



Heterophyes 

 /es 



Dicrp , 

 coehum 

 l&ncetxtum 



(*'" L s i< " 





Opisthorchis 

 felineus 



^B7 



Clonorchis Clonorchis 

 sinensis endemicus 



(Mo:! . | IJO,-) 



Fexsciolopsis 



bUSkli (fte,-Uo,.,y) 



Schistpsoma p ova0 o..in.us 

 j&poracum westginnanii , 



Schistosoma 



mansoi 





FIG. 20. Intestinal ova. Trematodes. Ova of intestinal parasites may possibly 

 occur in foods of vegetable origin contaminated by soil, sewage and fecal matter. 

 Note comparative size and the actual measurements according to the scale. It may 

 be mentioned that the extremely small seeds of Vanilla planifolia have been mistaken 

 for ova of intestinal parasites. (Stitt.) 



We are warranted in establishing a maximum limit as to the 

 number of organisms permissible in food substances. The 

 method of estimating the quality of foods based upon the number 

 of micro-organisms present has been tested out in different coun- 

 tries and has proven very reliable and satisfactory; and those who 



