OF EXPERIMENTAL WORK 23I 



Other Species and Reviews 



Giese, 1947. Review. 



Hollaender, 1954. Radiation Biology. Review. 



Langendorff, 1 93 1 . Psammechinus miliaris. 



Lee, 1947. Review. 



Miwa, Yamashita, and Mori, 1939, 1940, 1941. Pseudocentiotus depressus, Strongylocentrotus 



pulcherrimus . 

 Reiss, 1925. Probably Paracentrotus lividus. 



YOLK GRANULES 



Size. — 0.7 to I.I [A diameter (E. B. H. per E. N. Harvey, 1932a, E. B. Harvey, 1936) ; 

 0.3 pL (Heilbrunn, 1926a); i.o to 1.5 [x with electron microscope (McCulloch, 

 1952a). 



Shape. — Irregular or polyhedral (E. B. H. per E. N. Harvey, 1932 a, E. B. Harvey, 

 1936). Elliptical (McCulloch, 1952 a). 



Density. — Lighter than chromatophores ; form a layer above pigment layer and 

 below mitochondrial layer in centrifuged eggs (E. N. Harvey, 1932 a; E. B. Harvey, 

 1932, 1936, etc.). 



Approximately 1. 1035; the whole egg is approximately 1-0485 (Heilbrunn, 1926 a). 



Amount in Egg. — 27.2 % (E. N. Harvey, 1932a). 38 % (Costello, 1939). 



Stain. — With vital stains: Bismark brown, brilliant cresyl blue (faint), chrysoidin, 

 methyl violet (later), methylene blue (faint), neutral red, Nile blue, rhodamine, 

 toluidin blue (E. B. Harvey, 1941c). Fixed material. Yolk granules darken with 

 osmic acid (Lyon, 1907; E. B. Wilson, 1926); not stained with most protoplasmic 

 stains (Lyon, 1907; E. B. Wilson, 1926) ; pale blue with Benda-Kuhl (E. B. Wilson, 

 1926) ; stain with orange G but not iron haematoxylin (E. B. Harvey, 1940c). Table 8. 



Break Down. — In hypotonic sea water (D. L. Harris, 1943). On rupture of vitelline 

 membrane, and with cytolytic agents, e.g. saponin; no break down in absence of 

 calcium (Costello, 1932). 



