528 The American Naturalist. [June, 
ON SUCCESSIVE, PROTANDRIC AND PROTEROGYNIC 
HERMAPHRODITISM IN ANIMALS. 
By Tuos. H. Montcomery, JR., Pu. D. 
The term Successive Hermaphroditism has been introduced 
(Claparède, 9) to designate the kind of Hermaphroditism pre- 
sent in those animal forms, where the male and female gonads 
(germ glands) are in the adult separated from each other, and 
where the sexual products (sperma, ova) of the one sex develop 
earlier than those of the other. In all known cases of this 
_ form of Hermaphroditism, with perhaps the single exception 
of Microstoma lineare (Rywosch, 39, 40), the male products 
develop first. 
Successive Hermaphroditism is prevalent in the Plathelmin- 
thes (with the exception of the Nemerteans) and especially in 
the group of the  TuroeRaria. In the Cestodes it has been 
observed in Sol hal (Rodoz, 38)and by Zsch- 
hokke (48) in Cestodes phish present a large number of proglot- 
tids. Ercolani (15) has proved this phase of Hermaphrodit- 
ism among certain Distomids. In the Turbellaria it occurs in 
probably all the Acoela (Graff, 16). Among Rhabdocoelida in 
Convoluta (Claparède, 9), in Macrostoma hystrix and Promeostoma 
ovoideum (Graff, 16),in Graffilla muricicola (Ihering,18, Bohmig, 
5) and in G. brauni (Smidt, 42), in Prorhynchus (von Kennel, 
19, Moore, 32a). According to Du Plessis (13) it occurs in 
Plagiostoma lemani, though the accuracy of this observation 
has been doubted by Graff (l. c.) As mentioned above, in 
Microstoma lineare according to Rywosch (39, 40) the female 
organs develop before the male organs. Hallez (17) has 
observed this phase of Hermaphroditism in a number of the 
Tricladidea, and Loman (29) in Bipalium. It is the rule in the 
Polycladidea (Lang, 24). Finally, Successive Hermaphroditism 
has been noted among the Mollusca in Entoconcha (Müller, 
33), and in the Anatinacea (Babor, 2). 
In the case of Protandric Hermaphroditism the male and 
female gonads are united together into a single herma- 
