V. The Sponges of the „Willem Barents” Expedition 1880 and 1881

The Sponges described hereafter were all preserved in spirit. Those which were treated with chromic acid or some similar reagent were in a state that did not allow any investigation whatever. On the other hand some of the Sponges preserved in spirit were also in a bad condition, so that I could only make out something about the skeleton or the spicules. Some on the contrary were very well preserved so that even a few histological details could be observed. This is one of the reasons why I have treated the Sponges in the unequal manner that the reader will notice. Another reason is that I began my task when I was lecturer in the Hague and had much more time at my disposal than is now the case. I feel obliged to apologise. In the middle of 1882 I had the honour to be called as assistant at Prof. Dohrn’s Station in Naples and since then I could, of course, not devote very much time to my Polar Sponges. Still I had accepted the task and was thus obliged to finish it. I am convinced that many points more are to be found out with the material I had, but I thought it my duty not to spend more time. I hope the Commitee for publishing the results of the Barents-Expedition will excuse me for having made them wait so long a time and giving them so little.