biology, (ii, E, iii ; iv : F, i — viii.) Echin. 45 
viii* Developmental mechanics and Experimental Embry- 
ology: — General account; Maas (202). — General chapters on die 
Zeugung, die notwendigcn Stofle, der Eibau ; Przibram (262). — 
Eclnnoderm ovum and sperm-ovum illustrating cellular mechanics, 
segmentation, and development ; Gurwitsch (125) passim, with figg. 
after previous authors. -Experiments on segmentation, differentiation 
of tissues and organs, illustrated by Ech. and Ast . ; Maas (202) pp. 24, 
84. — Mesenchym-composition in Ech. larvae developed from inharmo- 
niously united blastomeres ; Driesch (86). — Equipotence of ectoderm 
and endoderm in larva of Asterias and Astropecten , larvae from 
fragments ; Driesch (87). — Relation of sizo and number of colls 
in larvae to chromosomes of ovum ; experiments on Echinus and 
Strong ylocentrotus \ Boveri (38): same continued by doubly fertilised 
Ech. ova ; Boveri (39). — Modification of segmentation by artificial 
increase of yolk ; Sanzo (285). — Retardation of development by 
increased temperature ; Peter (251 ). — Sphaerechinus gastrulae de- 
veloping rapidly in warmth vary in number of mesenchyme-cells 
more than do those developing slowly in cold ; Peter (252). — Effect 
of removal of oxygen on segmentation of sperm -ova of Arhacia ; Loeb 
( 184). — Action of spectrum rays, of ultraviolet light, of diffuse light 
on mitosis of sperm-ova of Echinus microtuberculatus ; Hertel (135). — 
Lithium bromide produces oxogastrulation in Ech . ; Gaubowski 
( 106). — Effects of acid, alkali, phonol-phthalein, and di-methvl-amido- 
azo-benzol on sperm-ova of Echinus ; Whitley (340) : ditto, and 
comparison with cell-growths in malignant disease ; Moore (217). 
Hybridization : — Boveri (38). — Echinus , Strongylocentrotus, and 
Sphaerechinus 9 x Antedon £ , and vice versa, brought to plutei, 
mother-characters only, also gastrulae from enucleated Ech. ova x 
Antedon ; Godlewski (115). — Echinus esculentus, Paracentrotus lividus , 
and Parechinus miliaris in various combinations, Plutei without 
entoderm from Echinus esculentus £ and Paracentrotus lividus 9 ; 
Garbowski (106). — Paracentrotus lividus 9 x Spatangus purpureus , 
Sphaerechinus granularis , and Parechinus microtuberculatus ; Gar- 
bowski (107) p. 614. 
Artificial Parthenogenesis : — General discussion ; Ariola (12a). — 
General summary of recent work, esp. Ariola, Yiguier, Loeb, Delage ; 
Loisel (193). — Summary and discussion of results obtained by Loeb 
et alii ; Verworn (327). — General discussion of physico-chemical 
theory of fertilisation ; Fischer (91a). — General discussion as to 
importance of nucleus; Ariola (12b). — Methods of inducing par- 
thenogenetic development of Ech. ova ; Driesch (85) p. 649. — Action 
of various salts and different concentrations on Asterias ova, fused 
blastulae ; Delage (70 ). — Asterias ova, increase of osmotic pressure 
not necessary, segmentation proceeding to blastula in a pure solution 
of manganese chloride, action of other salts, addition of calcium 
carbonate to carbonic acid produces fusion of numerous blastulae ; 
Delage (71). — Influence of temperature, of acid, on Ech. and Ast. 
ova, Ast. larva lives 4 months 19 days ; Delage (72). — Merogonic 
development sperm-ova Psammechinus and Strongylocentrotus , mitosis, 
cellular autotomy ; Krahelska (168). — Pieri’s ovulase disproved by 
experiments with Strongylocentrotus lividus ; Pizon (257). — Artificial 
formation of membrane in unfertilised ova of Strongylocentrotus pro- 
duced by concentrated solutions ; Loeb (185) : ditto by hypertonic 
sea-water and ethyl acetate, resulting in normal development ; Loeb 
(186) : Remarks on preceding ; Bohn (34) : Similar results by sub- 
stituting acetic, formic, or carbonic acid for ethyl acetate ; Loeb (187 
& 188) : ditto, by fatty acid, segmentation after subsequent exposure 
to hypertonic sea-water for a shorter period, discussion of membrane- 
