THE SCALES IN SOME TELEOSTEAN FISH. AS 
I cannot by any means prove what I affirm” ; he consequently 
proceeded to demonstrate his facts by means of sections 
through the scales. 
The paper ends with some very interesting remarks on the 
longevity and causes of death in fishes. 
During the eighteenth century many other writers made 
short, but unimportant, references to this subject, among them 
being Réaumur, Petit, Schaeffer, Ledermiiller, and Fontana, 
an admirable review of the literature of this period being 
given by Mandl (15). Réaumur gave the name “ Argentin ” 
to the translucent material on the surface of scales, and a 
rough chemical analysis of it was made subsequently by 
Heinrich Rose, and his results incorporated in a paper by 
Khrenberg (8). 
Kuntzmann (13) recognised that the variation in scales may 
be of generic value, and from his observations he was led to 
classify the scales of fishes into seven groups, which include, 
but under different names, the Ctenoid, Cycloid, and Clupeoid 
of to-day. 
The first investigator to seriously deal with the subject in 
a truly scientific manner was Agassiz in his work ‘ Recherches 
sur les Poissons Fossiles,’ in 1834. He here makes use of 
the scales as a basis for his classification of fishes into the 
Placoids, Ganoids, Ctenoids, and Cycloids, the latter in- 
cluding the Clupeoids. While mentioning that the scales 
are contained in pockets of the skin and are not retained in 
position by means of blood-vessels, as Leeuwenhoek appears 
to have believed, he nevertheless adopted the idea of the 
latter, slightly modified, in regarding each newly-formed scale 
as being successively attached to the lower surface of the 
preceding scale. 
The next paper of importance is that of Mandl, already 
referred to, in which the histological structure of the scale is 
examined in amore thorough and detailed manner. He drew 
attention to the fibrous substratum of the scale, which he 
accurately figures. The surface is described as composed of 
“corpuscules,” which Mandl recognised as being quite 
