THE ANNALS 



AND 



MAGAZINE OF NATURAL EISTORY. 



[SIXTH SERIES.] 

 No. 58. OCTOBER 1892. 



XXXI. — Notes on the Cuvierian Orcjans of Flolotliurla nig-ra. 

 Bj E. A. MiNCiriN, B.A., Assistant in the Department of 

 Comparative Anatomy, Oxford. 



[riate XVII.] 



The observations here recorded were made \>j me In the 

 summer of 1890, wlien I had the honour to occupy one of 

 the British Association tables in the Marine Biological 

 Laboratory at Plymouth, during the months of July, August, 

 and September. For the greater part of the time I was 

 engaged in studying the Gregarines of various marine 

 animals, but especially of Holothuria nigra. Of these I 

 obtained an abundance of living specimens, and so was able 

 to observe the Cuvierian organs in the fresh and living con- 

 dition. It was my intention at the time to work out fully 

 the structure and function of these remarkable organs ; but as 

 it has been impossible for me, owing to other work, to carry 

 out my purpose, it seemed best to publish at once the few 

 scattered observations I was able to make. 



1. Anatomical Relations. — The account of these organs 

 given by Bell (1) is inaccurate in certain details, which is 

 not to be wondered at, since he was only able to examine 

 spirit-specimens. He states (p. 375) that the organs arise 

 from the cloaca and that they differ from any yet described 

 by the fact that they are closely united together into a firm 

 bundle. Both these statements are erroneous and are due to 



Ann. & Mag. N. Hist. Ser. 6. Vol. x. 19 



