26 JOURNAL, R.A.S. (CEYLON). [VOL. XL. 



other part, is expressed by a suitable formula, and these 

 formulae are arranged in vertical columns. 



On the Utility of Zoological Tables. 



" I believe," says Professor Babbage, " my early perception 

 of the immense power of signs in aiding the reasoning 

 faculty contributed much to whatever success I may have 

 had." Such is the testimony of one of the greatest of 

 mathematicians to the power of signs. Professor Owen 

 long ago pointed out the need in which the anatomist stands 

 of using formulas : — " The entomologist has long found the 

 advantage of such signs as 6 ? , signifying male and female, 

 and the like, and it is time that the anatomist should avail 

 himself of these powerful instruments of thought, instruc- 

 tion, and discovery, from which the chemist, the astronomer, 

 and the mathematician have obtained such powerful results." 



Formulas are used by Zoologists to a certain extent. As 

 Professor Owen has said, it would be almost impossible to 

 compare the descriptions of the teeth of mammalia without 

 them. Of late years attempts have been made by various 

 authors to extend their use, more especially by the late 

 Professor Garrod. 



My object in the following table is four-fold : — (1) To 

 reduce the size of our zoological treatises ; (2) To show at a 

 glance the range of any particular structure in any given 

 group ; (3) To show what combinations of these structures 

 are found in nature, and the relationship of these combina- 

 tions to the food, habits, and geographical distribution of the 

 species which exhibit them ; (4) To place a powerful weapon 

 in the hands of the Taxonomist for the determination of 

 species. 



With regard to the first point it is unnecessary to dwell 

 on the great size and expense of our zoological works, 

 which the traveller cannot carry or the poor student afford. 

 In such works as Nicholson's "Indian Snakes" and 

 Beaven's " Freshwater Fishes of India," laudable attempts 

 have been made to furnish students with cheap and handy 



