THE 



VOYAGE OF H.M.S. CHALLENGEB. 



ZOOLOGY. 



KEPORT on the RADIOLARIA collected by H.M.S. Challenger during 

 the Years 1873-76. By ERNST HAECKEL, M.D., Ph.D., Professor of 

 Zoology in the University of Jena. 



PREFACE. 



THE significance of the Radiolaria in regard to the relations of life in the ocean has been 

 increased in a most unexpected manner by the discoveries of the Challenger. Large 

 swarms of these delicate Rhizopoda were found not only at the surface of the open ocean 

 but also in its different bathymetrical zones. Thousands of new species make up the 

 wonderful Radiolarian ooze, which covers large areas of the deep-sea bed, and was brought 

 up from abysses of from 2000 to 4000 fathoms by the sounding machine of the 

 Challenger. They open a new world to morphological investigation. 



When ten years ago (in the autumn of 1876) I accepted the enticing invitation of 

 Sir Wyville Thomson to undertake the investigation of these microscopic creatures, I 

 hoped to be able to accomplish the task with some degree of completeness within a period 

 of from three to five years, but the further my investigations proceeded the more 

 immeasurable seemed the range of forms, like the boundless firmament of stars. I soon 

 found myself compelled to decide between making ' a detailed study of a selection of 

 special forms or giving as complete a survey as possible of the varied forms of the whole 

 class ; and I decided upon the latter course, having regard both to the general plan of the 

 Challenger Reports, and to the interests of our acquaintance with the class as a whole. 



(ZOOL. CHALL. EXP. PAET XL. 1887.) Rr A 



10. 



