The present study was carried out to investigate the histological and histochemical changes in the
liver and skin on different developmental stages of Egyptian toad Bufo regularis to be used as a
histological key for such species. Our experiment started when tadpoles began to feed. The adapted
embryos are divided into 3 large tanks of 200 embryos each, collections of samples started from
feeding age every three days. Both histological and histochemical results showed that the general
architecture of the different organs was correlated with the state of development, i.e. larval, metamorphic
and post-metamorphic. They, therefore, displayed different characteristic features depending
on the investigated developmental stage starting from the larval stage (stage 44) and
ending with the post-metamorphic stage 66.