344 SYDNEY J. HIOKSON. 



Preface. 



The work that is recorded in these pages has occupied a 

 considerable portion of my time for the past two years, and 

 was entirely conducted in the morphological laboratory at 

 the University of Cambridge and the Marine Biological Asso- 

 ciation's laboratory at Plymouth. In some respects it is not 

 so complete as I had hoped it would be. My original inten- 

 tion was to publish with the account of the anatomy of the 

 species a description of its development and spermatogenesis, 

 but unforeseen difficulties presented themselves, and I have 

 decided to postpone the publication of the results I have already 

 obtained until they are more complete. The development of 

 Alcyonium can only be studied in the months of December and 

 January, when the investigations are frequently interrupted or 

 delayed by storms and rough weather. I have experienced 

 very great difficulty in keeping the young embryos alive when 

 I have been successful in effecting artificial fertilisation of the 

 ova. 



If I am successful this winter in obtaining the stages in 

 development that I have not hitherto obtained, I hope to pub- 

 lish an account of the maturation and fertilisation of the ovum 

 and the development in the course of next year. 



As I felt that the determination of the chemical constitution 

 of the homogeneous substance composing the bulk of the 

 mesogloea required considerable skill and time, which I did not 

 possess myself, I entrusted this portion of the work to Mr. 

 W. L. Brown, of St. John's College, Cambridge, and his paper, 

 which accompanies this, is a valuable addition to our knowledge 

 of the chemical constitution of the Coelenterate tissues. 



Section I. — History of Investigations. 



The common ** dead men's fingers" of our coasts was con- 

 sidered by the ancients to be one of those substances formed 

 by the churning of the sea waves. It received its name 

 Alcyonium probably from Alcyone, daughter of ^olus and 



