Cytochemistry of Protozoa, with Particular Reference to the Golgi Apparatus and the Mitochondria

Abstract

This chapter describes cytochemistry of protozoa with emphasis on the Golgi apparatus and the mitochondria. The vast studies on cytoplasmic inclusions of the subclass Phytomastigina pertain to the order Euglenoidina. In addition to the chloroplasts, stigma, and associated structures the euglenoids have been considered to have four types of cytoplasmic inclusions: (1) mitochondria or chondriome, (2) vacuome, (3) Golgi material, and (4) mucous bodies. The Golgi material found in the various classes of protozoa has been shown to be homologous with the Golgi dictyosomes of all metazoan cells except the neurons of vertebrates. In a large number of species belonging to all the five classes of the protozoa, studies with the electron microscope have made abundantly clear that the Golgi material exists in the form of typical dictyosomes, exactly similar to those of the metazoan cells. Each dictyosome consists of very flat saccules, the walls of which enclose a slit-shaped area and appear as very conspicuous membranes. It is the walls of these saccules that show osmiophily whereas the contents of the saccules always appear brighter.