A lattice arrangement of mitochondria is rare in vertebrate cells, but can be observed here in mature Sertoli cells of the Xenopus testes. Multiple parallel fenestrated layers of cristae are interconnected by regularly arranged tubular elements, and shown here in different planes of section. Image from Kalt (1974) Anat. Record. 182:53-60. Figure 244 from Chapter 7 (Mitochondria) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. A PDF copy of the accompanying chapter is available on the ASCB’s BioEDUCATE website.