528 Mr. W, S. Macleay's Anatomical Observations 



larly those of M. Savigny, attracted a considerable portion of 

 public attention. 



Although it is a proposition now almost undisputed, that Zoo- 

 logy cannot be satisfactorily studied without comparative ana- 

 tomy* being taken for its basis, perhaps it may not be amiss to 

 cite as examples of the truth of this assertion the singular disco- 

 veries of Savigny on the compound Tunicata. The wonderful 

 facts which this distinguished naturalist has recorded could never 

 have been discovered by him had he confined his attention to 

 external appearances. Disdaining to rest contented with the 

 manufacture of names, he employed himself in the investigation 

 and generalization of physiological facts ; and his discovery of 

 compound Tunicata I conceive to be such as may deservedly be 

 placed at the side of that of the metamorphosis of Batrachian 

 reptiles, or any other important physiological fact whatever. 

 Dissection, indeed, must always be resorted to when we wish to 

 understand the structure of the Tunicata, whether simple or com- 

 pound ; and the naturalist who contents himself with describing 

 the external appearance of an Ascidia may remain even more 

 ignorant of the nature of the inclosed animal, than that person 

 is of Mollusca who knows no more of them than the shells they 

 once inhabited. Hence it is that Cuvier says, " La forme exte- 

 rieure des Ascidies etant sujette k beavicoup de variations, leur 

 surface ofFrant peu de differences, leur couleur ne se conservant 

 pas apr^s la mort, et difFerant probablement pendant la vie selon 

 I'age et les lieux ou elles ont pris leur croissance, il est malaise de 

 les distinguer surement quand on n'a pas recours a leur interieur." 

 So well aware was Aristotle of this truth, that he has given us 

 an anatomical account of such species of Ascidice as he was 

 acquainted with, so detailed and so accurate as to puzzle his 



* Something like the converse of tliis proposition is also true ; namely, that no com- 

 parative anatomist is worthy of the name who is not also a zoologist. 



commen- 



