GERM-CELL HISTORY IN THE BROOK LAMPREY 121 



Gould, Harley N. 1917 Studies on sex in the hermaphrodite mollusc Crepi- 



dula plana. II. Influence of environment on sex. Jour. Exp. ZooL, 



vol. 23. 

 GuTHERZ, S. 1912 Ueber ein bemerkenswerthes Strukturelement (Hetero- 



chromosome?) in der Spermiogenese des Menschen. Arch. mikr. Anat., 



Bd. 79. 

 Outer, M. 1909 a The spermatogenesis of the domestic chicken (Gallus gallus 



dom.). Anat. Anz., Bd. 34. 



1909 b The spermatogenesis of the domestic guinea (Numida mele- 



agus dom.). Anat. Anz., 34. 



1916 Studies on the chromosomes of the common fowl as seen in testes 



and in embryos. Biol. Bull., vol. 31. 

 Hargitt, C. W. 1906 The organization and early development of the egg of 



Clava leptostyla. Biol. Bull., vol. 10. 

 Hargitt, Geo. T. 1913 Germ cells of coelenterates. I. Campanularia flexu- 



osa. Jour. Morph., vol. 24. 

 Hatta, S. 1892 On the formation of the germinal layers in Petromyzon. Journ. 



Coll. Sc, Imp. University Japan, vol. 5. 



1907 On the gastrulation in Petromyzon. Id., vol. 21. 

 Henking, H. 1891 Untersuchungen ueber die ersten Entwicklungsvorgange 



in den Eiern der Insekten. Zeitschr. wiss. Zool., Bd. 51. 

 Hertwig, R. 1905 Ueber das Problem der sexuellen Differenzierung. Verh. 



deutsch. zool. Gesellsch., Vers. 15. 



1906 Weitere Untersuchungen ueber das Sexualitatsproblem. Id., 

 Vers. 16. 



1907 Weitere Untersuchungen ueber das Sexualitatsproblem. Id., 

 Vers. 17. 



1908 Neue Probleme der Zellenlehre. Arch. Zellforsch., Bd. 1. 

 Hoffman, C. K. 1886 Zur Entwicklungsgeschichte der Urogenitalorgane bei 



den Anamnia. Zeitschr. wiss. Zool., Bd. 44. 



1892 Etude sur le developpement de I'appareil urogenital des oiseaux. 



Verh. d. kon. Akad. d. Wiss. Amsterdam, 1892. 



D'Hollander, F. G. 1904 Recherches sur I'oogenese et sur la structure et la 

 signification du noyau vitellin de Balbiani chez les oiseaux. Arch. 

 Anat. micr., T. 7. 



Howes, G. B. 1891 On some hermaphroditic genitalia of the codfish (Gadus 

 morhua), with remarks upon the morphology and phylogeny of the 

 vertebrate reproductive system. Journ. Linn. Soc, vol. 23. 



Janssens, F. a. 1904 Das chromatische Element wahrend der Entwicklung 

 des ovocytes des Triton. Anat. Anz., Bd. 24. 



1905 Spermatogenese dans les Batraciens. III. Evolution des auxo- 

 cytes males du Batracoseps attenuatus. La Cellule, T. 22. 



Jarvis, May 1908 The segregation of the germ cells of Phrynosoma cornutum. 

 Preliminary note. Biol. Bull., vol. 15. 



Jordan, H. E. 1914 The spermatogenesis of the mongoose; and a further com- 

 parative study of mammalian spermatogenesis with special reference 

 to sex chromosomes. Pub. Carnegie Inst. Washington, No. 182. 



