Anomalies in the Genital Organs of Toads. 173 
this case is similar to that found by Spengel, ’76, in Bufo cinereus. 
In the other individual Cerruti found that each Bidder’s organ had 
developed into a rudimentary ovary which contained many large ova 
in various stages of degeneration and also ova that appeared like 
normal odcytes except that they did not have any yolk spherules. 
In the second cases noted by Cerruti the condition of the sex- 
glands is much like that in the hermaphroditie Bufo lentiginosus 
described above. In both of these individuals it is evident that the 
rudimentary ovaries were derived from cells which normally would 
form a Bidder’s organ. In young toad tadpoles, as shown in a 
previous paper (King, 08a), the cells which are destined to form 
Bidder’s organ are directly continuous with the primordial germ- 
cells that later form the sex-gland; they are similar to the germ-cells 
in structure, and they develop like the germ-cells up to the synizesis 
stage. These facts seem to me to prove conclusively that the cells 
which form Bidder’s organ are degenerate germ-cells. It is not sur- 
prising, therefore, that occasionally these cells develop into ova which 
apparently have a normal structure. 
Many instances of hermaphroditism have been recorded for various 
species of frogs. Cases similar to those found in Bufo, where a 
rudimentary ovary has developed at the anterior end of a testis, 
have been described by Marshall, ’84, Kent, ’85, and Ridge- 
wood, °88; the reverse condition, with the ovary below the testis, 
has been found by Bourne, ’84, in Rana temporaria. Marshall, 
and also Smith, *90, have reported cases in which one of the sex- 
glands in an individual was an ovary and the other a testis. This 
latter form of hermaphroditism is extremely rare among amphibians, 
and it has not yet been found in Bufo. Evidently hermaphroditism 
occurs much less frequently among the Urodela than among the 
Anura, as only two cases have as yet been reported for this group 
of amphibians. La Valette St. George, 93, has given a_ brief 
description of a case of hermaphroditism in Triton teeniatus, and 
Knappe, ’86, has noted the presence of a Bidder’s organ in a young 
salamander; neither investigator gives any details regarding the 
structure of the ovo-testes in these forms. ; 
Abnormalities of the kind described above, whether they occur 
