220 ALPHABETICAL COMPILATION 



finds susceptible period (M/25 to M/ioo NaCN) at time of astral development, 

 sperm and cleavage asters; and Heilbrunn (1920a) with 0.005% KCN at spindle 

 stage. Cleavage blocked (with M/200 KCN) in monaster stage (Just, 1928 a); (with 

 1.6 X io~* M KCN) in early prophase (Clowes and Krahl, 1934b, 1935; Krahl, 

 1950, Clowes, 1 951 ); in early prophase or "streak" stage, with or without pyocyanine 

 (Runnstrom, 1935 a). No definite rhythm (Blumenthal, 1930; A. Scott, 1950). 



Ether. — Most susceptible during cleavage, first and second (Spaulding, 1904). 



Heat. — 32" to 36 °C. Most susceptible just before first and second cleavage; dif- 

 ferent from cold (Lyon, 1904b). 



Hypertonic Sea Water. — Most susceptible 5 to 1 5 minutes after fertilization and im- 

 mediately before and during each cleavage (A. R. Moore, 19 15). 



Hypotonic Sea Water. — Most susceptible and most cytolysis during formation of the 

 cleavage furrow, due to increased permeability of plasma membrane, decreased 

 electrical polarization and increased surface tension ; same for first, second and third 

 cleavages (R. S. Lillie, 1916b). During "pause" and especially during late anaphase 

 just before egg elongates (Just, 1928 b). Increasingly susceptible, with cytolysis from 

 2 to 6 minutes after fertilization till cleavage; and same for saponin (Page, 1929a). 

 Most susceptible in anaphase and early telophase, least in prophase; reverse for 

 saponin (Keltch, Wade, and Clowes, 1934). 



Mechanical Shocks. — Most susceptible immediately after fertilization (Mathews 

 and Whitcher, 1903). 



Nitrogen Mustard. — Mitosis stopped in early prophase, "streak" stage (E. B. H. 

 and Cannan, 1943 unpub., but see Oilman and Phillips, 1946, literature list # 52, 

 p. 436, incorrectly quoted on p. 413; correctly stated by E. B. Harvey, 1946 a, 

 p. 261). Cornman (i95od), however, found no phase block but overall slowing. 



Oxygen-Lack. — Most susceptible (hydrogen atmosphere) 10 to 15 minutes after 

 fertilization ; same as for KCN (Lyon, 1 902) . Cleavage blocked (nitrogen atmosphere) 

 before fusion of pronuclei, with or without pyocyanine (Runnstrom, 1935 a); at 

 prophase (Clowes and Krahl, 1940). 



Phenols And Derivatives. — Block to cleavage in early prophase (Clowes and Krahl, 

 1934a, b, 1935, 1936a; Krahl, 1950; Clowes, 1951). A. Scott (1950) finds no phase 

 inhibition. 



Radium. — Most susceptible in metaphase (Packard, 19 16). 



Salts. — NaCl, KCl, CaCU, MgClj. Most susceptible during cleavage, first and 

 srcond (Spaulding, 1904). Effect of salts on resistant period (Page, 1929a). See 

 Chambers and Chambers (1949). 



Saponin. — Same as for hypotonic sea water (Page, 1929 a); most susceptible in 

 prophase, least in telophase, reverse of hypotonic sea water (Keltch, Wade, and 

 Clowes, 1934). 



Ultraviolet Light. — (Blum and Price, 1950a). 



X-Rays. — Most susceptible at prophase (Henshaw, 1938c; E.B.Harvey, 1946a). 

 Refractory period (Blum, et al., 1951). 



Other Species and General References 



Brachet, 1950. Chemical Embryology, p. 157, general. 



Herlant, 19 14, 1918b, 1920. Paracentrotus lividus. 



Just, 1922b, c. Echinarachnius parma, hypotonic sea water. 



Runnstrom, 1933. P. lividus, respiration rhythms. 



Zeuthen, 1949, 1950. S. franciscanus, Dendraster, Ps. miliaris, respiration rhythms. 



Zeuthen, 1951. Ps. microluberculatus, colchicine. 



ROENTGEN RAYS 



See X-Rays 



