1895.] Hermaphroditism in Animals. 529 
phrodite gland (ovotestis), but the male elements are 
developed earlier than the female. Protandric and Successive 
Hermaphroditism are, however, not to be very sharply distin- 
guished from one another. For example, in the Molluscs, 
where both these phases occur, we find all intermediate stages 
between (1) forms having a simple ovotestis, in which the male 
elements develop first (e. g. Ostrea); (2) forms, where in certain 
acini of a protandric ovotestis only male, in other acini only 
female elements are produced (e. g. Lobiger) ; and lastly (8) in 
forms where there are two or four separate genital glands, the 
male elements developing first (e. g. Entoconcha and the Ana- 
tinacea). According, though it is not proved that in all cases 
Successive Hermaphroditism has been evolved out of Pro- 
tandric Hermaphroditism, this has very probably been the 
case in certain animals, as Entoconcha and the Anatinacea, 
which shows that these two phases of Hermaphroditism are 
closely connected with each other. 
Protandric Hermaphroditism has been demonstrated in re- 
presentatives of a large number of groups. Among sponges 
in Aplysilla violacea (Lendenfeld, 26) and Amorphina coalita 
(Topsent, 44); I wish here to express my thanks to my former ' 
teacher, Prof. F. E. Schulze of Berlin, for calling my attention 
to these two references. Among Nematodes in Allantonema 
mirabile (Leuckart, 28), and Filaria rigida (zur Strassen, 43). 
Among Nemertinea in Tetrastemma kefersteint (Marion, 30), and 
observed further by me (32) in Stichostemma eilhardi. Accord- 
ing to Korschelt’s (21) observations it is present in the poly- 
chete Genus Ophryotrocha. Wheeler’s (46) account of the 
development of the gonads of Myzostoma would show that in 
this form Protandric Hermaphroditism exists, though Beard’s 
(3, 4) studies on the contrary would explain the state of affairs 
on the “ complemental male” theory. Among Isopod Crus- 
tacea in three genera of the Cymothoidz,-Nerocila, Cymothoa, 
Anilocra (Mayer, 31). Among Echinoderms we find it in 
Asterina gibbosa and Amphiura squamata (Lang, 25). But 
especially in the Mollusca is Protandry of frequent occurrence. 
So it occurs in the Solenogastra (Wiren, 47, Koren, and Daniels- 
sen, 20). In the pulmonate Gasteropoda in Lymnæus (Eisig, 14), 
