MARINE BIOLOGICAL STATION AT PORT ERIN. 35 



down to the greatest known depths of from four to five 

 thousand fathoms — nearly six statute miles from the surface. 

 We can trace the gradual growth of Thomson's ideas in regard 

 to the sea with the natural widening of his scope — from 

 collecting as a student on the shores of the Firth of Forth 

 to dredging as a young professor along the coasts of Ireland, 

 and then to the successive deep-water expeditions in the 

 surveying vessels " Lightning " and " Porcupine," and finally 

 to the great world-wide exploring voyage of the " Challenger." 

 We can also trace the steps in his Echinoderm studies which 

 seem to have led him to the fruitful field of deep-sea exploration. 

 Palaeontological investigation suggested work on living 

 Crinoids, and the news that a strange new stalked Crinoid 

 (Rhizocrinus), related to the fossil Apiocrinidae, had been 

 found living in Northern seas induced him, in 1866, to visit 

 Professor Michael Sars at Christiania, and examine for himself 

 the remarkable collection of rare animals that his son, George 

 Ossian Sars, had brought up from deep water (over 300 fathoms) 

 in the Lofoten fjords. He was struck by their novelty and 

 deep interest and by their resemblance to and bearing upon 

 some of the extinct animals of former geological periods, and 

 especially of the Chalk. 



Thus inspired, he urged his friend Dr. W. B. Carpenter, 

 with whom he was then working at the later development of 

 Antedon, to join him in endeavouring to promote an expedition 

 to explore the deep waters of the Atlantic along the north-west 

 coasts of Europe. Dr. Carpenter's powerful advocacy induced 

 the Council of the Royal Society to use its influence with the 

 Hydrographer, with such success that the Admiralty consented 

 to place first one and then another small surveying steamer 

 at the disposal of a Committee of scientific experts, for expedi- 

 tions under the leadership of the two enthusiasts. After the 

 first summer a third Naturalist of European fame, Dr. Gwyn 

 Jeffreys, author of the five volumes on British Conchology, 



