PROTOPLASM OF PROTOZOA 81 



the beta granules (mitochondria) resulted in the death of the amoeba. 

 Singh (1939) has also centrifuged A. proteus 'Y,' and found the order of 

 layering to be: nutritive spheres, nucleus, crystals, neutral red bodies, 

 mitochondria, cytoplasm, contractile vacuole, and fat. 



Patten and Beams (1936) centrifuged Euglena and found that the 

 chloroplasts form a middle belt, having on the centrifugal side paramy- 

 lum and neutral red bodies, while the clear cytoplasm containing the small 

 spherical mitochondria is at the centripetal pole. In Menoidium the 

 heaviest inclusions are the paramylum and neutral red bodies; in Chi- 

 lomonas the starch and neutral red bodies are heaviest. Johnson (1939) 

 has confirmed the results of Patten and Beams; in Euglena rubra, how- 

 ever, hematochrome is present and is displaced to the centripetal pole 

 with mitochondria. 



King and Beams (1937) ultracentrifuged Paramecium; in this form 

 the various components and inclusions were layered in the following 

 order from centrifugal to centripetal: crystals in vacuoles, compact 

 chromatin of the macronucleus, food vacuoles and neutral red inclusions, 

 achromatic matrix of the macronucleus, endoplasm, large clear vacuoles, 

 and fat. Here the chromatin may be removed from the achromatic matrix 

 of the macronucleus; the chromatin regenerates a macronucleus; the 

 achromatic matrix persists for some time and apparently interferes with 

 subsequent divisions. Browne (1938) has ultracentrifuged Spirostomum 

 and has found the contents of the cell to be layered as follows : centrif u- 

 gally located are the mitochondria, food vacuoles, and macronucleus; cyto- 

 plasm; Golgi bodies; and centripetally, vacuoles. 



Daniels (1938) has used the ultracentrifuge in a study of gregarines; 

 here the paraglycogen and chromidial granules are heaviest; next, the 

 mitochondria and nucleus; cytoplasm; then the larger Golgi bodies; and 

 lightest the smaller Golgi bodies and fat globules. In the gregarines 

 studied the karyosome moved centrifugally in the nucleus, and the con- 

 tents of the deutomerite layered independently of those in the primlte 

 because of the presence of the transverse septum. 



It is obvious that the centrifuge may serve as an important research 

 tool for the identification and study of the form, relative volume, and 

 other characteristics of the components and inclusions found in proto- 

 plasm. For example, Holter and Kopac (1937), by cutting amoebae in 

 half after centrifuging, were able to demonstrate that the enzyme dipepti- 



