528 Mr. W. S. Maczeav’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 à beaucoup de variations, leur 
surface offrant peu de differences, leur couleur ne se conservant 
pas apres la mort, et differant probablement pendant la vie selon 
l'age et les lieux ou elles ont pris leur croissance, il est malaisé de 
les distinguer surement quand on n'a pas recours à leur interieur." 
So well aware was Aristotle of this truth, that he has given us 
an anatomical account of such species of Ascidiæ as he was 
acquainted with, so detailed and so accurate as to puzzle his 
* Something like the converse of this proposition is also true; namely, that no com- 
parative anatomist is worthy of the name who is not also a zoologist. 
commen- 
