IX THE HISTORY AND SCOPE OF ZOOLOGY 335 



1870 were his pupils and acknowledged his leadership. 

 The most striking feature about Johann Muller's 

 work, apart from the comprehensiveness of his point 

 of view, in which he added to the anatomical and 

 morphological ideas of Cuvier a consideration of 

 Physiology, Embryology, and microscopic structure, 

 was the extraordinary accuracy, facility, and complete- 

 ness of his recorded observations. He could do more 

 with a single specimen of a rare animal (e.g. in his 

 memoir on Amphioxus, Berlin, 1844) in the way of 

 making out its complete structure than the ablest of 

 his contemporaries or successors could do with a 

 plethora. His power of rapid and exhaustive obser- 

 vation and of accurate pictorial reproduction was 

 phenomenal. His most important memoirs, besides 

 that just mentioned, are those on the anatomy and 

 classification of Fishes, on the Ccecilians, and on the 

 developmental history of the Echinoderms. 



A name which is apt to be forgotten in the period 

 between Cuvier and Darwin, because its possessor 

 occupied an isolated position in England and was not 

 borne up by any great school or university, is that of 

 John Yaughan Thompson, who was an army surgeon, 

 and when past the age of forty, being district medical 

 inspector at Cork (1830), took to the study of marine 

 Invertebrata by the aid of the microscope. Thompson 

 made three great discoveries, which seem to have 

 fallen in his way in the most natural and simple 

 manner, but must be regarded really as the outcome 

 of extraordinary genius. He showed that the organ- 

 isms like Flustra are not hydroid Polyps, but of a 



