BIHAXG TILL K. SV. VET.-AKAD. HANDL. BAND 27. AFD. IV. N:0 6. 5 



teile von Mesothuria intestinalis dnrch Herrn Professor Théel 

 steht in Anssicht. Derselbe hat gleichfalls in diesem Jahre, 

 und zwar friiher als ich, die Zwitterigkeit bei diesem Tiere 

 beobachtet." 



If Ave take into consideration that this is really tbe only 

 positive information on hermaphrodism in the pedate Holo- 

 thurids and, besides, that we are greatly in want of a more 

 detailed description of the genital organs in this group af 

 animals, it is thonght that the following communication may 

 be of some interest and may contribute, to a certain extent, 

 to widen our present knowledge of the subject. 



It is a well known fact that several of the apodous Holo- 

 thnrids, for example Sjmapta digitata (Mont.), Synapta in- 

 hcerens (O. F. Muller), and probably also several other spe- 

 cies belonging to this genus are hermaphrodite, and for a 

 long time it was supposed that all the forms of the Synap- 

 tidse had the two sexes nnited in the same individual. Låter 

 on it was proved by several investigators that this is not in 

 conformity with the truth, bnt, that, on the contrary, the sexes 

 are distinct in many forms of apodous Holothurids. If we 

 neglect the family Molpadidse which probably has the sexes 

 separate,^ all the Holothurids provided with feet are consi- 

 dered to have the sexes distinct, except Ananus holothurioides 

 and Ocnus javanicus which, according to Sluiter,^ are herma- 

 phrodite. 



Nevertheless, Ludwig of Bonn,^ our best authority respec- 

 ting the echinoderms, has pronounced in bis splendid descrip- 

 tion of the "Seewalzen", that these very cases are unsatis- 

 factorily known and are greatly in want of further investi- 

 gation. It is true that Sluiter has not given reasons enough 

 for his interpretation, which may be understood from the 

 following citation taken from his paper, "Ueber einige neue 

 Holothurien von der Westktiste Java's." Here he says with 

 regard to Ananus holothurioides: "Einige dieser Follikel sind 

 männliche und einige weibliche Zeugungsorgane. Welche 

 aber männlich welche weiblich sind, ist äusserlich nicht zu 



' Ludwig, H., Die Seewalzen. — Bronn's Klassen nnd Ordnungen des 

 Thier-Reichs. II, 3, p. 182. Leipzig 1889—1892. 



- Ueber einige neue Holothurien von der Westktiste Java"s. — Natuur- 

 kundig Tijdschrilt voor Nederlandsch-Indie. XL. Batavia 1881. AVith 7 

 plates. 



3 1. cit., p. 183. 



