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SCIENCE 



[N. S. Vol. XXXVII. No. 951 



these the editor lias largely supplemented the 

 original drawings from figures by Savigny 

 and Milne Edwards. But the usefulness of 

 the book will be by no means restricted to stu- 

 dents who are countrymen of the authors. 

 It will undoubtedly take a conspicuous place 

 in the working library of specialists in the 

 group wherever located, as it already has in 

 that of the reviewer. 



Divers reflections are induced by reading 

 the divers things said in these volumes by 

 divers persons. The brief, straightforward ac- 

 count by Canon Norman in Volume I. of how 

 the monograph came to be undertaken re- 

 lates that Alder was requested by the keeper 

 of the zoological department of the British 

 Museum to prepare a " Catalogue of British 

 Tunicata " as one of the series of catalogues 

 then being issued by the Museum; that Alder 

 at once took up the task and pushed it to the 

 exclusion of everything else; and that after 

 several years' work when he reported the 

 manuscript ready to be turned in he was in- 

 formed by the keeper (with the deepest regret) 

 that somebody had withdrawn the grant for 

 publishing the catalogues, and that conse- 

 quently his work could not be published. In 

 the absence of information to the contrary this 

 looks like a flagrant breach of contract on the 

 part of the Museum, and reminds one of the 

 frequent charge that institutions and govern- 

 ments hold themselves less bound by contracts 

 than individuals are supposed to be held. If 

 this be so the fact can only mean that com- 

 munities in which it is true are still in an 

 immature stage of advancement in civiliza- 

 tion, 90 that as time goes on and with it prog- 

 ress it will be impossible for such cases of 

 broken faith to occur. 



The extent to which embryological knowl- 

 edge may modify interpretations based solely 

 on anatomical knowledge could hardly be 

 more strikingly illustrated than by Hancock's 

 ideas about the homologies of tunicate organs. 

 He knew almost as much as we of to-day know 

 about the gross structure of full-grown ascid- 

 ians, yet he considered the close kindred of the 

 group with the polyzoa to be fully established I 

 The proposal made by several zoologists to 



separate the ascidians from the molluscs he 

 looked upon with great disfavor, and his ef- 

 forts to prove the resemblance between the 

 respiratory apparatus of an ascidian and that 

 of a bivalve mollusc seem curious enough to 

 us now. Of course he was familiar with the 

 tadpole stage of the individual ascidian, 

 though he thought it a secondary acquirement. 

 But it is not alone with reference to these 

 broad generalizations as to group afiinities and 

 classification that discoveries in development 

 have changed morphological ideas. There is 

 hardly a page of Hancock's essay that does not 

 contain some interpretation, expressed or im- 

 plied, which does not accord with present 

 views. Kowalevsky's epochal " Entwickel- 

 ungsgeschichte der einfachen Ascidien " was 

 published in 1866, and although Hancock's 

 " On the Anatomy and Physiology of the 

 Tunicata " did not appear until the next year, 

 there is no indication that the English com- 

 parative anatomists had read the memoir of 

 the Russian embryologist. 



In an addendum to the biographies of the 

 authors which introduce the second volume, 

 Canon Norman remarks that Alder and Han- 

 cock were "naturalists of a by-gone time." 

 " With only very moderate advantages," he 

 says, " as regards early education, they pro- 

 gressed greatly in knowledge by private study 

 as years went by. An intense love of nature 

 absorbed them, and they realized that every- 

 thing else must be sacrificed to allow them to 

 find out nature's secrets." When one recalls 

 that these were only two among a considerable 

 number of Britishers of that period who, 

 largely self-trained, passed all or a great part 

 of their lives in unremitting toil as investiga- 

 tors of nature, and did this without compen- 

 sation or institutional aid, he can but be 

 mindful how unqualifiedly true is Norman's 

 remark about a by-gone age. Undoubtedly 

 the refinements of method in nearly all de- 

 partments of research, necessitated by the ad- 

 vancements that have been made, account in 

 large measure for the almost entire disappear- 

 ance of this type of scientific men. The pro- 

 fessionalizing and institutionalizing of science 

 in our day as compared with former days have 



