ance, were till now absolutely unknown as regards their development. 

 Thus e. g. of the Echinoidea the great and important families Diaclema- 

 tida 3 , Temnopleurida? and Echinometridae are, with the exception of 

 one or two forms of each, confined to the Indopaciiic (and, moreover, the 

 few forms which do occur in European and American Seas have not been 

 made the object of embryological study till now). Only the family Arbaciida- 

 is confined to the European and American seas and the family Echinida 1 

 for the main part so. For the rest the European-American Echinoid-fauna 

 forms only a small outskirt of the Indo-Pacific fauna, and, accordingly, 

 even if we knew the development of all the European-American forms, 

 such knowledge would be fragmentary and altogether insufficient for 

 forming a decisive judgment of the classifies tory value of the larva?. 



For a long time it has been my ardent desire to tackle this subject, 

 taking up the study of the Echinoderm larva? methodically from the point 

 of view expressed here. As an introduction a visit was made at the marine 

 Laboratory at Plymouth in the summer of 1913, especially in order to 

 become acquainted with the excellent methods of rearing marine larva? 

 worked out there through the efforts of the director, Dr. E. .1. Allen and 

 his fellow workers. A preliminary report on the researches made there, 

 resulting in the rearing of several forms the larva? of which were till 

 then unknown, was given in the paper "Notes on the development of 

 some British Echinoderms". 1 ) But the main thing was, of course, to 

 undertake such investigations in the Pacific regions. This was at length 

 made possible for me through liberal grants from the Carlsberg Fund and 

 from the Government (the "Kommunitet" Fund), enabling me to spend 

 more than two years there in different localities. As the Expedition 

 had several other objects besides the study of the Echinoderm larva? the 

 plan of the voyage could not be laid exclusively with regard to the latter 

 purpose, but it need scarcely be stated that every opportunity was seized 

 for making the most out of this special subject. 



The first place visited was the Philippines, where Zamboanga, on I he 

 Southern end of Mindanao, and Jolo were the main spots chosen for 

 working places. No embryological researches were carried out here 

 this being mainly due to lack of experience, not of undertaking artificial 

 fertilization, but of what may be done even where all laboratory facilities 

 are wanting, as they were here - an experience which there was rich 

 opportunity of gathering by the continued work during the voyage. 



In Japan, the next place visited, the Biological Station at Misaki, at 

 the Sagami Bay, offered splendid opportunities for carrying out embryo- 

 logical work, and the author's efforts in this direction were very success- 



*) Journ. Mar. Biol. Assoc. N. S. X. 1913. 



