506 NICHOLAS ZOGKAFF. 



This bone basis is very fine and consists of a typical (partly 

 described by Kolliker) 1 bone tissue, in which star-like bone 

 elements are not seen ; when the section is made in a direction 

 parallel with the surface of the lamellse one can distinguish 

 in the thickness of the bone ramous canals (described by 

 Kostler), which make it look something like the dentine of 

 teeth. 



The bony basis is covered by a periosteum, which consists of 

 very fine long and flat cells, and passes into a connecting 

 adipose tissue, which, on its external surface, becomes a 

 connective tissue (cutis) ; the cutis is covered by an epithelium ; 

 among the cells of this can be seen numerous goblet-like 

 mucous cells. 



From the above one sees that the labyrinthine apparatus is 

 not a very complicated organ, and by its structure approaches 

 the general typical structure of the skin coverings of fishes ; 

 but, as we shall see directly, special elements of the labyrin- 

 thine apparatus appear to be strongly modified. 



Let us begin with the layer of connective tissue which lies 

 next to the periosteum. This connective tissue consists of 

 star-like cells with very long processes, and with a small 

 cell-body and a little nucleus. These cellules, connected by 

 their outshoots, form a netted tissue (fig. 8, ctj. ad.) ; between 

 the meshes of this tissue are big, fat, adipose cells, that make 

 a fresh tissue look very odd ; but generally there remain 

 no traces of fat in the sections, because the preliminary pre- 

 paration in spirit, chloroform, &c, dissolves the fat. 



It is only in objects prepared in osmic acid that the fat 

 is retained where it is when sections are made (fig. 8) ; but 

 meanwhile an organ without fat differs very much from one 

 with it, as the fat in a tissue does not lie in mass, but in 

 small round groups (cj't. ad.). The skin covering over these 

 groups of fat is lifted or raised, whereas between them the 

 coverings are much thinner, and consequently the surface of 



1 A. Kolliker, " Ueber verschiedene Typen in der microscopiscben Structur 

 des Skelettes der Knockenfiscbe," ' Verhandlungen der physicalisch- 

 mediciuiscber Gesellscbaft zu Wiirzburg,' Band viii. 



