174 Tlelen Dean King. 
in the sex-glands of young or of adult amphibians, seem explicable 
only on the assumption that the primitive amphibians were herma- 
phroditic, and that in the course of their evolution this primitive 
hermaphroditic condition has given place to the bi-sexual condition 
found at the present time. Although a rudimentary sex-gland (Bid- 
der’s organ) is found only among the Bufonide at present, traces 
of the primitive hermaphroditie condition still exist in other forms, 
as is shown by the fact that in some individuals the genital glands 
contain both ova and spermatozoa. Such individuals, however, are 
only rudimentary hermaphrodites, since apparently only one kind 
of germ-cell ever becomes functional. The spermatozoa are prob- 
ably a much more specialized type of cell than the ova, and it might 
be expected, therefore, that the male germ-cells would assume the 
characteristics of ova more frequently than that the female germ- 
cells would be able to develop into spermatozoa. ‘This is doubtless 
the reason that, with but very few exceptions, all of the anomalies 
found in the sex-glands of adult amphibians occur in individuals 
which must be considered as males since only the sperm-cells are able 
to reach maturity. 
LITERATURE. 
Bourne, A. G. 
1884. On Certain Abnormalities in the Common Frog (Rana temporaria). 
Quart. Journ. Micr. Sci., Vol. XXIV. 
CERRUTI, A. 
1907. Sopra due casi di anomalia dell’ apparato reproduttore nel Bufo 
; vulgaris Laur. Anat. Anz., Bd. XXX. 
Cone, F. J. 
1895. A Case of Hermaphroditism in Rana temporaria. Anat. Ang., Bd. 
DiGi : 
FRIEDMANN, IF. 
1898. Rudimentiire Wier im Hoden von Rana viridis. Arch. mikr. Anat., 
Bd. LII. 
HAECKEL, E. 
1874. Anthropogene oder Entwickelungsgeschichte des Menschen. Leip- 
21g. 
Hertwia, R. 
1906. Weitere Untersuchungen itiber das Sexualitiitsproblem. Verhandl. 
deutsch. zool. Gesellsch. 
1907. Untersuchungen iiber das Sexualitiitsproblem. III. Verhandl. 
deutsch. zool. Gesellsch. 
