THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[SIXTH SERIES.] 

 No. 48. DECEMBER 1891. 



LI. — On the Development of llolothurians. 

 By Dr. Hubert Ludwig *. 



My sincere thanks are clue to the Royal Academy of Sciences 

 for having several years ago furnished me with the means of 

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

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

 until last spring 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 



* Tianslated from the ' Mathematische und naturwisseuschaftlicbe 

 Mittlieilungen aus den Sitzimgsberichten der Kunigiich I'reussischeu 

 Akademie der Wissenschafteu zu Berlin,' Heft ii. Feb. 1891, pp. [1791 85- 

 98 [192]. 



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

 yihhosa (Zeitscbr. f. wiss. Zool. Bd. o7, 1882). 



Ann. & Mag. N. Hist. Ser. G. Vol. viii. 29 



