44 MR. J.W. CLARK ON THE NARWHAL. [Jail. 17. 



"common to the maxillary and intermaxillary," or contained "in 

 the intermaxillary only " *, a mistake which F. Cuvier has copied f. 

 The wall of the alveolus is so thin on the underside in a full-grown 

 animal that it chips off in maceration (fig. 2). 



It has been asserted that the tusk of the Narwhal may be deve- 

 loped indifferently on the right side or on the left. This view was 

 originally advanced by the two Cuviers and Lacepede %, and has 

 since been brought forward again by Meckel§ and Rapp||, and more 

 recently by Lilljeborg, who, in his paper on the Scandinavian Cetacea, 

 says, " the long and sharp tusk, which is generally in the left side 

 of the upper jaw, is spiral to the left. The spiral ridges run to the 

 left, even when the tusk is in the right side of the upper jaw"^]". 

 In the Swedish original of the paper the passage runs as follows:— 

 " The tusk, when on the right side of the upper jaw, has its spiral 

 dextrorsal, instead of sinistrorsal" **. It was to controvert this state- 

 ment that Reinhardt wrote his paper. 



An examination of the ground of this assertion introduces us to 

 the most fruitful of all sources of error in descriptions of the Narwhal, 

 namely, erroneous figures. It is based on the woodcut given by 

 Blasius tf> in which the right tusk is undoubtedly developed, with a 

 dextrorsal spiral, and with the skull twisted towards the right instead 

 of towards the left. But a careful examination shows, as Reinhardt 

 points out, that Blasius has borrowed his Cetacean illustrations in 

 general from G. Cuvier, from Brandt and Ratzeburg, and from F. 

 Cuvier — and this one in particular, on a slightly reduced scale, from 

 the last author, who has himself taken it from his brother's work, 

 without observing that his engraver has reversed it in making the 

 copy, the right side appearing as the left, and vice versa. The same 

 mistake has been made by Owen 1%, in borrowing Sir E. Home's 

 figure ; and by Pander and D' Alton §§. In figures of the entire ani- 

 mal the spiral is as often dextral as sinistral ; but these are, one and 

 all, so full of errors of every sort that we need not stop to consider 

 them more particularly ||[|. 



It is true that the testimony of Fabricius may be advanced in 



* Ibid. p. 321. Comp. also ' Regne Animal,' ed. 1829, i. p. 292. 



t Histoire des Cetaces, p. 230. 



J Lacepede (C6taces, p. 147), " Elle (la dent) est situee au cote droit ou au 

 cote gauche de la niackoire superieure." Gr. Cuvier (Oss. Foss. v. p. 321), " Dans 

 le male il n'en sort ordinairement qu'une des deux (dents), le plus souvent eelle 

 du cote gauche." F. Cuvier (Ceiaces, p. 237), " La defense .... qui se trou- 

 verait tantot au cote droit, tantot au cote gauche." 



§ Meckel, ' Vergleichende Anatomie,' ed. 1829, iv. p. 516. 



]| Rapp, ' Die Cetaeeen,' p. 46. 



if Lilljeborg, ' Scandinavian Cetacea,' ed. Ray Society, p. 244. 



** Reinhardt, I. c. 



tt Saugethiere Deutschlands, p. 525, fig. 282. Compare Gr. Cuvier, ' Ossemens 

 Fossiles,' v. plate xxii. ; Brandt and Ratzeburg, ' Medizinische Zoologie;' and 

 F. Cuvier, ' Cetaces,' plate 17. fig. 3. 



| J Odontography, plate 87. fig. 1. Compare Sir E. Home, ' Lectures on Com- 

 parative Anatomy,' ii. pi. 42. 



§§ Skelette der Cetaceen, p. 2, tab. v. fig. a and b. 



|| || Compare, for instance, the figure in Trans. Roy. Soc. 1813, plate vii. fig. 2. 



