These were assessed at intervals of 1, 6, 18, 24 and 48 hours and 1, 4 and 8 weeks.

It would appear that administration of aflatoxin B₁ induced a marked nucleolar alteration seen from 6 hours after the injection. No significant alterations were noted in animals treated with a small amount of aflatoxin G₁, but injection of a larger amount of aflatoxin G₁ induced nucleolar alterations similar to aflatoxin B_l treatment. The nucleolar change was characterized by segregation of the granular and fibrillar elements.

All three groups showed cytoplasmic changes, such as dilation of rough endoplasmic reticulum with detachment of ribosomes, hyperplasia of smooth endoplasmic reticulum, increased numbers of lipid droplets and microbodies.

Autoradiographic studies have shown the absorbtion of both aflatoxin B₁ and G₁ in parenchymal cells, but aflatoxin B_l was absorbed more intensely than G_l, especially in the nucleus. Autoradiographic findings in electron microscopy showed a marked difference in the size grains between aflatoxin B₁ and G₁, aflatoxin G₁ being 1arger than aflatoxin B₁.