[Electron microscope study of "Bacillus thuringiensis" var. "Israelensis" sporulation and crystal biogenesis (author's transl)].

The sporulation and crystal development of Bacillus thuringiensis serotype H-14 was described for a wild spore- and crystal-forming strain and for a mutant crystal but non spore-forming strain. The special nature of the israelensis var. consisted in the composite structure of the crystal, made of a number of components differing in size, shape and electron density. The components were formed in a single inclusion or sometimes separately inside the same bacterial cell.