XIV. ECHINODERMA. 
44 Eel tin. 
vii. Post-larval Growth-stages :— 
c. Neanic >S 'cutella patagonensis, movement of anus with growth; 
Ortmann (212) p. 59. " 
viii. Developmental mechanics and Experimental Embry¬ 
ology :—General accounts,—of recent researches; Hickson (128).— 
Of Experimental Embryology; Van Beneden (284): ditto (pp. 8-249) 
including special account of researches on Echinoderms (pp. 109-121) 
with reff. to papers by Driesch, Fiedler, Loeb, Morgan, Ziegler, and 
Zoja (p. 121); Korschelt & Heider (158).—Of Experimental Em¬ 
bryology of Ech.; Przibram in Hamann (119) pp. 1213-1295.—Of 
researches, chiefly on fragmentation; Michel (204).—Of experiments 
on fertilisation and parthenogenesis in Ech., esp. Echinus esculentus, 
and Ast .; Bryce (36). 
Hybrid larvae, Strongylocentrotui lividus £ x Sphaerechinus granu- 
laris $, series of variations between the parent forms, no characters 
obviously due to either father or mother; Steinbruck (267). 
Inorganic substances necessary for development of Ech., chlorine, 
hydroxyl, natrium, potassium, calcium from earliest stages, and 
sulphate, carbonate, magnesium, for later stages, their various effects; 
Herbst (123). 
Ovum of Asterias dies from natural causes in a few hours, but is 
saved by fertilisation; Loeb (172).—Heath of Arbacia ovum retarded 
by fertilisation or by brief treatment with certain salts, e.g. potassium 
cyanide, after which sexual or par then ogenetic development is possible, 
but lowering temperature or lack of oxygen does not greatly prolong 
life, confirmation from Asterias; Loeb & Lewis (173).—Production of 
an immune serum and its action on ova of Ech. and Ast .; Hungern 
(75) p. 50. 
Composition of nucleus of Ech. ovum, especially in the light of 
double fertilisation, criticism of Delage, Driesch, Wilson and others; 
Boveri (29).—Segmentation in ova of Echinus after some chromo¬ 
somes or the centrosome have been excised; centrosomes appear de 
novo, but original number of chromosomes is not restored ; Stevens 
(270).—Studies in gastrulation, determination of parts, development 
of Ecli. gastrulae from fragments of blastomeres; Driesch (72).— 
Exogastrulae, results of Driesch and Herbst discussed ; Bhumbler 
(237) p. 452, f. 23. 
Artificial parthenogenesis,—theoretical discussion; Delage (60) 
p. 135.—Loeb’s work critically discussed ; Boveri (30).—Methods 
and sources of failure, strength of solution, temperature, agitation, 
differences in these respects between Ech. and Ast. ova; Loeb (170).— 
Causes, viz., raising or lowering of temperature, shaking, saline 
solutions, so-called hybridisation, results obtained with Mediterranean 
species of Sphaer echinus, Toxopneustes , and Arbacia ; Viguier (287).— 
Lowering of temperature results in irregular segmentation of Arbacia 
ova, but swimming larvae from Asterias ova, no segmentation results 
from raising temperature; Greeley (109).—Shaking induces a 
slight and incomplete parthenogenesis in Ast. ova ; Delage (64) 
p. 231.—Effect of potassium cyanide on fertilized ovum of Arbacia , 
weak solution slightly hastens development, prolonged exposure pro¬ 
duces disintegration, similar effects due to lack of oxygen ; Lyon 
(180).—Mitosis of unfertilised Toxopneustes ova treated with MgCl., 
fresh formation of centrosomes; Wilson (296), & (297) p. 506.—Seg¬ 
mentation induced in unfertilised ovum of Strongylocentrotus lividus 
by solutions of magnesium chloride, strychnine, nicotine, and liyo- 
scyamin, while ergotine had no effect; detailed examination of the 
mitosis; Wassilieff (293).—Carbon dioxide, most effective agent; 
