Wilder.] 328 [June 21, 



Dr. J. E. Gray " observed that in his opinion internal characters 

 were of little use in Zoology; (Proc. Zool. Soc, Apr. 11, 1867, 

 and Journ. of Anat. and Phys., 2, 371); while Parker admits 

 the value of external characters, but says the mind will not rest in 

 these outward things, and that the skeleton, nervous system, diges- 

 tive, respiratory and vocal organs are very important. 1 Testimony 

 to the zoological value of the skeleton is given by Agassiz, 2 but 

 Owen speaks again as follows : " Guided by the seldom failing law - 

 that distinctive characters are most strongly developed in the periph- 

 eral portions of the body," etc., 3 and further believes that the " form 

 and disposition of the scales of the legs of birds have afforded dis- 

 tinctive characters to the zoologist" (63, 2, 232). 



Further reference to the opinions of various authors, respecting 

 the taxonomic value of different systems of organs is given by Rolle- 

 ston (294, xxi, note), and the matter is briefly discussed by H. 

 Allen 4 . 



It is quite probable that in practice all the above authors have 

 been more definite than their language would imply, and that they 

 have more or less perfectly discriminated between the value of an or- 

 o-an for one kind of group, and that which it might have for another ; 

 this is done by Wyman 5 when he says that the " teeth of mammals 

 afford the surest indication of zoological affinities," because he 

 means that for the determination of groups within the class the teeth 

 have a high morphical value. Flower questions this fact, 6 but admits 

 the principle, as had Turner before him, 7 by attaching morphical 

 value to characters of the base of the skull within the order, Car- 

 nivora. 



Giinther likewise discriminates within the order, when he says, 8 

 " under these circumstances, I still feel satisfied to distribute the 

 fishes on the basis of Muller's ordinal arrangement into minor natural 

 groups, whether called families, groups or genera ; and in my opin- 

 ion, there is no character equal in importance to that of the structure 

 and position of the fins ; as they are in immediate connection with 



i Trans. Zool. Soc, v. 149, 1862. 



- Anat. des Salmones, p. 1. 



s Memoir on Dinornis, p. 78. 



* Outlines of Comp. Anat.. and Med. Zool. p. 13, 1869. 



5 Lectures- on Comp. Physiology, 1849, p. 24. 



« Proc. Zool. Soc, 1849, p. 5. 



i Turner, EL N. f P. Z. S. 1848. 



» Catal. of Acanth. Fishes. Preface. 1861. • , 



