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lusca, and Radiata his researches have been so important and suc- 

 cessful, that what he has accomplished for either alone would suffice 

 to establish for him a high scientific reputation. 



His earliest labours were chiefly directed to the class Crustacea ; 

 of which (after having published numerous Memoirs on its various 

 subdivisions) he produced in 1837-1840 an elaborate Monograph, 

 Anatomical, Physiological, and Systematic, which is universally re- 

 garded as of pre-eminent merit, not only for its richness of detail, 

 but also for the value of the general doctrines relating to Homolo- 

 gies, Development, Geographical Distribution, and other points of 

 the highest physiological interest, which are enunciated in its pages. 

 The Annelida have also occupied much of Professor Milne-Ed- 

 wards' s attention ; his researches on their structure, and especially 

 on their development, were among the first, and are still among the 

 most important of those numerous contributions which have of late 

 added so much to our knowledge of this class ; and they have served 

 as models for all who have followed in the same path of inquiry. 

 Some of the most important of these researches were made on the 

 coast of Sicily, whither Professor Milne-Edwards was sent by the 

 French Government in charge of an Expedition for the study of 

 Marine Zoology. 



His researches on the Circulation of the Mollusca, undertaken to 

 clear up the difficulties in the asserted phlebenterism of the Nudi- 

 branchiata, have introduced a new and satisfactory mode of regard- 

 ing the circulation of the Invertebrata generally, which throws light 

 upon many obscurities, and solves many perplexities. Again, his 

 researches on the Compound Ascidians have led to an entirely fresh 

 appreciation of some of the most important points in the history of 

 that group, which had escaped the penetration of Savigny ; more 

 especially by making it clear that propagation by gemmation, which 

 had been previously supposed to be a Zoophytic character, is equally 

 true of the lower Mollusca ; thus was the way prepared for the re- 

 ception of the Bryozoa into that sub-kingdom. 



The labours of Professor Milne-Edwards upon Zoophytes have 

 not been less important or less successful than in the departments 

 already named. He was (with his collaborateur M. Audouin) the 

 first to observe and to appreciate the essential distinctions between 

 the so-called Polypes of the Flustra and its allies, and the true 



