BLOCK

block, mark eliezer (c. 1723-1799), german naturalist, was born at ansbach, of poor jewish parents, about 1723. after taking his degree as doctor at frankfort-on-oder he established himself as a physician at berlin. his first scientific work of importance was an essay on intestinal worms, which gained a prize from the academy of copenhagen, but he is best known by his important work on fishes (see ichthyology). bloch was fifty-six when he began to write on ichthyological subjects. to begin at his time of life a work in which he intended not only to give full descriptions of the species known to him from specimens or drawings, but also to illustrate each species in a style truly magnificent for his time, was an undertaking the execution of which most men would have despaired of. yet he accomplished not only this task, but even more than he at first contemplated. he died at carlsbad on the 6th of august 1799.