107 



Norvegiae". 2. livr. Bergen. 1856) are given credit of being the first 

 to have studied the development of Holothurians. The figures here 

 published show that in reality 0rsted was the first to make these 

 observations. But not only the direct development of the young, 

 also the larval glandular organ and the fact that the number of 

 tentacles increases from 5 to 12 during the development of the 



Fig. 1. Developmental stages of anchors and anchor-plates in Synaptula vivipara 

 (= hgdriformis) drawn by A. S. 0rsted in 1845. 



specimen were discovered by 0rsted. Even the enervation of the 

 eye-spots,, which was denied by Haman, Semon and Ludwig, 

 is dissected out and drawn, and the presence of eyes is further- 

 more used in the diagnosis of the genus Synaptula. 



The first discoverer of the ciliated funnels is Mertens who 

 writes: "Kein Respirationsbaum, statt desselben am Gekröse zahl- 

 reiche kleine Cylinder, wie wir sie schon ganz ähnlich in der Holo- 

 thurie Nr. 6 bemerkt haben" (cfr. Ludwig: Revision der Mertens- 

 Brandt'schen Holothurien, pag. 579). These "cylinders" are the 

 large, up to 1 mm long clusters of funnels in Polycheira mfescens 



