126 EXTERNAL FACTORS III. 7 



et sur la parthenogenese artificielle chez les Echinodermes, Arch. ZooL 

 Exp. et Gen. (3) ix, 1901. 



M. A. FISCHER. Further experiments on artificial parthenogenesis 

 in Annelids, Amer. Journ. Pliys. vii, 1902. 



W. J. GIES. Do spermatozoa contain an enzyme having the power of 

 causing the development of mature ova? Amer. Journ. Phys. vi, 1901-2. 



A. W. GREELEY. Artificial parthenogenesis in the star-fish produced by 

 lowering the temperature, Amer. Journ. Phys. vi, 1901-2. 



A. W. GREELEY. On the analogy between the effects of loss of water 

 and lowering of temperature, Amer. Journ. Phys. vi, 1901-2. 



A. W. GREELEY. On the effect of variations in the temperature upon 

 the process of artificial parthenogenesis, Biol. Bull, iv, 1903. 



R. HERTWIG. Ueber die Entwicklung des unbefruchteten Seeigel- 

 eies, Festschr. Gegeribaur, Leipzig, 1896. 



S. J. HUNTER. On the production of artificial parthenogenesis in 

 Arbacia by the use of sea-water concentrated by evaporation, Amer. 

 Journ. Phys. vi, 1901-2. 



J. W. JENKINSON. Observations on the maturation and fertilization 

 of the egg of the Axolotl, Quart. Journ. Micr. Set. xlviii, 1904. 



K. KOSTANECKI. Ueber die Veranderungen im Inneren des unter 

 dem Einfluss von KCl-Gemischen kunstlich-parthenogenetisch sich ent- 

 wickelnden Eis von Mactra, Bull. Intern. Acad. Sci. Cracovie, 1904-5. 



J. LOEB. On the nature of the process of fertilization and the artificial 

 production of normal larvae (Plutei) from the unfertilized eggs of the 

 sea-urchin (two papers), Amer. Journ. Phys. iii, 1899-1900. 



J. LOEB. Further experiments on artificial parthenogenesis, and the 

 nature of the process of fertilization, Amer. Journ. Phys. iv, 1900-1. 



J. LOEB. Experiments on artificial parthenogenesis in Annelids 

 (Chaetopterus), Amer. Journ. Phys. iv, 1900-1. 



A. P. MATHEWS. Artificial parthenogenesis produced by mechanical 

 agitation, Amer. Journ. Phys. vi, 1901-2. 



T. H. MORGAN. The fertilization of non-nucleated fragments of 

 Echinoderm eggs, Arch. Ent. Mech. ii, 1895-6. 



T. H. MORGAN. The production of artificial astrospheres, Arch. Ent. 

 Mech. iii, 1896. 



T. H. MORGAN. The action of salt solutions on the unfertilized and 

 fertilized eggs of Arbacia, Arch. Ent. Mech. viii, 1899. 



T. H. MORGAN. Further studies in the action of salt solutions and 

 other agents on the eggs of Arbacia, Arch. Ent. Mech. x, 1900. 



E. B. WILSON. A cytological study of artificial parthenogenesis in 

 sea-urchin eggs, Arch. Ent. Mech. xii, 1901. 



8. THE CHEMICAL COMPOSITION OF THE MEDIUM 

 By means of solutions of alkaloids and other substances the 

 brothers Hertwig have been able to incite very remarkable cyto- 

 logical changes in the eggs of sea-urchins (Strongylocentrotus). 



