l80 ALPHABETICAL COMPILATION 



Chemical Properties. — A "haptogen" membrane consisting mainly of protein (R. S. 

 Lillie, 1909). Probably an "albuminoid"; insoluble in concentrated H2SO4, HCI, 

 KOH, NaOH, etc. (E. N. Harvey, 1910b). Not a lipoid because not soluble in ben- 

 zol, ether, alcohol, saponin, etc. (Loeb, 1913 a, p. 214). A protein gel with little or 

 no lipid (Heilbrunn, 1915a). Insoluble in KCI, urea or trypsin after hardening, 

 soluble while elevating (Kopac, 1940a, 1941 a; Chambers, 1942, 1944; A. R. Moore, 

 1949a, p. 243 footnote, re Kunitz, 1932 unpub.). For Psammechinus miliaris see 

 Monroy and Runnstrom (1948). Contains ribonucleic acid (Lansing and Rosen- 

 thal, 1949). 



Oil Coalescence. — Prevented by fertilization membrane (Kopac, 1940a, 1941a; 

 Chambers, 1944). 



Permeability. — Freely permeable to salts of sea water, relatively impermeable to 

 sugar and proteins (E. N. Harvey, 1910b). Freely permeable to salts, impermeable 

 to colloids like egg albumen and difficultly permeable to sugar (R. S. Lillie, 1911a). 

 Permeable to water, salts and sugar, impermeable to colloids (Loeb 1913 a, p. 208; 

 19 1 6, p. 108). Permeable to electrolytes when fully formed (Heilbrunn 1915a). 



Distance from Egg Surface. — Normally 3 to 5 (x (E. B. Harvey per E. N. Harvey, 

 1932 a; E. B. Harvey and Anderson, 1943; et al.). May be 6.5 \l (E. B. H.). It may 

 be closely adherent under various conditions so as to be difficult to detect (by cold, 

 32 °C., E. N. Harvey, 1910b; Just, 1928a; et al.), or it may be widely separated (by 

 urea, Moser, 1940). Collapses in i or 2 % egg albumen (Loeb, 1913 a, p. 208; Heil- 

 brunn, 1915a, 1924a; R. S. Lillie, 1918b); in 2 % Witte's peptone (Carrey, 1919); 

 with blood albumen (Chambers, 1942). 



Longevity. — Membranes obtained from hatching blastulae dissolve almost at once 

 (due to hatching enzyme present). Membranes obtained in distilled water may re- 

 main intact for 12 hours (E. B. Harvey and Anderson, 1943). 



Function. — Not to prevent other sperm from entering as was originally suggested 

 by Fol (1877), and maintained by many others (e.g.. Kite, 19 12). It is not necessary 

 for development (McClendon, 1912b; Glaser, 1913; E. N. Harvey, 1914; Chambers, 

 1930; Loeb, 1915c, though earlier, 1913a, p. 233, he thought it was necessary). It is 

 probably protective. See Plate XVI, Photograph 7. 



A Second Fertilization Membrane. — Many investigators have found that a fertilized 

 egg cannot be fertilized again, even if the fertilization membrane has been removed 

 (Loeb, 19 1 6, p. 85; F. R. Lillie, 19 19, p. 25, 161). Loeb (1913 a, p. 234) however, 

 thought that fertilization could be superimposed on artificial parthenogenesis, and 

 a second membrane would form after the one due to parthenogenesis had been 

 shaken off (Loeb, 1913a, p. 234, 1914b, 1915a, b). This was shown not to be the 

 case, but to be due to insufficient treatment with the parthenogenetic agent, by 

 C. R. Moore (1916, 1917); F. R. Lillie (1914, 1919. P- 167, 1921a); Just (1922a): 

 F. R. Lillie and Just (1924, p. 502). 



But more recently, Sugiyama (1947, 1951) in the case of fertilized eggs (Strongylo- 

 centrotus pulcherrimus ) , and Ishida and Nakano (1947, 1950) in the case of partheno- 

 genetic eggs, state that refertilization can take place if the eggs are washed in 

 Ca-Mg-free sea water after (usually) shaking off the first membrane. See Part II, 

 Fertilization, Chapter 13, sections o and p. (p. 107, 108). 



Removable by: — (i) Shaking (McClendon, 1910b; E. N. Harvey, 191 1; F. R. 

 Lillie, 1914; Plough, 1927; Kopac, 1940a; et al.). Shake the eggs immediately after 

 the fertilization membranes have formed, in a test tube about one quarter full of 

 eggs and sea water, violently, with thumb over open end, for about 30 seconds 

 (E. B. H.). (2) Straining through bolting cloth (Just, 1939a, b, p. 199 footnote). 

 (3) Sucking through a fine pipette (Plough, 1927; E. B. Harvey, 1932). (4) Micro- 

 manipulation (Chambers, 1942). (5) Distilled water, one minute after formation 

 of membranes; empty membranes are recoverable (E. B. Harvey and Anderson, 

 1943). (6) Sea water from around hatching blastulae which contains "hatching 



