Stniclure of the Scales of Fishes. 287 



or that all the lamellae do not afford instances of this trans- 

 formation. But, in either case, we cannot affirm that the 

 edge of the inferior lamella constitutes these lines. We have 

 in the first instance, seen the difference in the structm^e of the 

 edge of the scale and the lines : the direction of the latter is 

 sometimes entirely opposite to that of the edge ; at other times, 

 the lines situated between two canals are interrupted, and cross 

 each other ; while the corresponding edge of the scale follows 

 a uniform direction, &c. 



With regard to the other opinion, in favour of a formation 

 from the upper layer, independently of the under one, we yet 

 know too little of the matter to venture on an affirmation to 

 that effect. Perhaps the study of the development of scales in 

 young individuals, may throw light on a question full of interest 

 in regard to the physiology of the tegumentary appendages. 



The silvery matter deposited on the under side of the scale, 

 on a particular membrane, consists of crystals, whose form is 

 represented at Fig. 16. 



EXPLANATION OF PLATE III. 

 Fig. 



1. Scale of the Perch. 



2. ... Carp. 



3. ... Cobitis fossilis. 



4. Portion of a scale oiAcerina vulgaris, shewing the longitudinal canals. 



5. ... Mullus harbatus, 



6. ... Serranus Scriba. 



7. ... Percarina Demidoffii. 



8. ... Scincus. 



9. ... Corvina nigra. 



10. ... Motella tricirrata, 



11. ... Mullus barbatus. 



12. ... Serranus Scriba. 



13. Portion of a scale of the same, shewing the corpuscles. 



14. Inferior layer of a scale. 



15. Teeth of a scale of Corvina nigra. 

 IG. Silvery matter. 



liemarks occasioned by Dr MandVs Observations on the Struc- 

 ture of the Scales of Fishes. By M. Agassiz.* 



I WAS informed at the time that M. Mandl had read to the 

 Academy, on the 24th June 1839, the results of the observa- 



* In a letter a<ldres8od to the; Academy of Sciences, Coniptes Rendu 

 a Fi:vrier,p. 191. 



