Behavior of the Germ-cells 183 



sometimes sterile. This sterility is due apparently, in some cases 

 at least, to irregularities in the division of the germ-cells. When 

 we recall that at one stage in the development of the germ-cells 

 there may be a pairing and subsequent fusion of the ma- 

 ternal and paternal chromosomes, we can readily imagine that 

 any differences in their behavior at this time might lead to 

 disastrous results. 



LITERATURE, CHAPTER XI 



BoRDET. Contribution a I'Etude de I'lrritabilite des Spermatozoides chez 



les Fuccacees. Bull, de I'Acad. Belgique. 3""' ser. XXVII. 1894. 



BovERi, Th. Ein Geschlechtlich erzeugter Organismus ohne miitterliche 



Eigenschaften. Sitz.-ber. d. Ges. f. Morph. u. Phys. Munchen, V, 



1889. 



Ueber die Befruchtungs- und Entvvicklungsfahigkeit kernloser Seeigel- 



eier. Arch. f. Entw.-Mech. II. 1895. 

 Ueber den Einfluss der Samenzelle auf die Larvencharaktere der 



Echiniden. Arch. f. Entw.-Mech. XVI. 1903. 

 Noch ein Wort ueber Seeigelbastarde. Arch. f. Entw.- Mech. XVII. 



BuLLER, A. H. The Fertilization Process in Echinoidea. Report 70, Meet. 

 Brit. Assoc. 1901. 

 Is Chemotaxis a Factor m the Fertilization of the Eggs of Animals? 



Quart. Jour. Micro. Sc. XLVI. 1903. 

 Contributions to our Knowledge of the Physiology of the Spermatozoa 

 of Ferns. Ann. of Botany, XIV. 1900. 

 Calkins, G. Studies on the Life-History of Protozoa, I. The Life-Cycle 

 of Paramoecium Caudatum. Arch. f. Entw.-Mech. d. Organismen. 

 XV. 1902. 

 Studies on the Life-History of Protozoa, III. The six hundred and 

 twentieth generation of Paramoecium Caudatum. Biol. Bull. III. 

 1902. 

 Delage, Y. Embryons sans noyau maternel. C. R. Acad, des Sc. V. 

 , 1898. 



Etudes sur la Merogonie. Arch, de zool. experim. et gen. V. 1899. 

 Sur I'interpretation de la fecondation merogonique et sur une theorie 

 de la fecondation normale. Arch, de zool. experim. et gen. VII. 

 ,1899. 



Etudes experimentales sur la maturation cytoplasmique et sur la 

 parthenogenese experimentale. Arch, de zool. experim. et. gen. IX. 

 1901. 

 Dewitz, J. Ueber Gesetzmassigkeit in der Ortsveranderung der Sperma- 

 tozoen und in der Vereinigung derselben mit dem Ei. Arch. f. die 

 gesammte Physiol. XXXVIII. 1886. 

 Driesch, H. Ueber rein miitterliche Charaktere an Bastardlarven der 

 Echiniden. Arch. f. Entw.-Mech. VII. 1898. 

 Ueber Seeigelbastarde. Arch. f. Entw.-Mech. XVI. 1903. 



