TIIH ANNALS 



AND 



MAGAZINE OF NATURAL KISTORY. 



[SIXTH SERIES.] 

 No. 48. DECEMBER 1891. 



LF. — On the Development of Holothurians. 

 By Dr. Hubert Ludwig *. 



My sincere thanks are due to tlie Royal Academy of Sciences 

 for having several years ago furnislied me with the means of 

 making a second t sojourn at the Zoological Station at Naples. 

 For a long time I was prevented from going ; and it was not 

 until last sjjring that I was able to make the journey, the 

 results of which I now have the honour to communicate. 



I had proposed to myself, as the principal object of my 

 investigations, to trace the development of a Holothurian as 

 far as possible into the post-embryonic and post-larval life, 

 and selected for the purpose the common Mediterranean 

 Cucumaria Planci, since, from previous experiments, it 

 appeared to be the most suitable of Mediterranean sea-slugs 

 for prolonged culture in aquaria, and is universally regarded 

 as a thoroughly typical Holothurian. At the same time I 

 made further progress with my monograph on the Mediter- 

 ranean Echinoderms, which I had undertaken for the ' Fauna 



* Translated from the ' Mathematiscbe und naturwisseuscbaftliclie 

 Mittheilunpeu aus den Sitziingsberichten der Konitjiicli l^reussisclien 

 Akademie der ^\issenschaften zu Berlin,' Heft ii. Feb. 1891, pp. [179] 85- 

 98 [192]. 



t The chief result of a former stay was the development of Astcrina 

 yihJjosa (Zeitschr. f. wiss. Zool. Bd. 37, 1882). 



Ann. ct- Mcuj. N. Hist. Ser. 6. Vol. viii. 29 



