DR. KLEIN ON KILAMENTS OF PERITONEUM OF THE FROG. 43 



iierve-preparations which after twelve years' keeping in glyce- 

 rine are unaltered. But this fact does not reader impossible 

 the occurrence of a primary cliange disturbing the molecules 

 from their original inter-relation before observation com- 

 menced. At the present moment, I do not intend to assert 

 that such changes do actually occur, nor do I intend at 

 present to take up the explanation of the phenomena here 

 related. Both points, however, are worthy of the notice of 

 microscopists, as affecting the character of a valuable reagent. 



On Remak's Ciliated Vesicles and Corneous Filaments 

 of the Peritoneum of the Fhog. By Dr. E. Klein, 

 Assistant- Professor at the Brown Institution Laboratory. 



E.EMAK describes (Muller's ' Archiv,' 1841, p. 4-51) in the 

 mesogastrium of the frog, especially in the neighbourhood of 

 the pancreas, parasitic formations, -.'^th-l line in length, 

 -j-L-ijth-yVth line in thickness, of cylindrical shape, of solid 

 consistence, and varying in colour from a clear to a dark 

 brown. It is but seldom that they eud in a point at either 

 extremity ; in most part they appear transversely truncated. 

 Most of them are enclosed in the tissue of the mesentery, only 

 a few projecting above the surface. They lie either in groups, 

 crossing each other irregularly with microscopic vesicular 

 cavities or larger filaments, are so embedded, that they are 

 fixed with their two extremities in two ])erfectly different 

 cysts, formed of concentric layers of " cell fibres," while their 

 middle portion exhibits no special envelope, or also, on its 

 part, possesses a similar layer of cell fibres as a covering, 

 which gradually pass into the fibres of the two ends. Very 

 often, according to Hemak, such (dumb-bell) shaped bodies 

 are connected with each other like a chain, or it sometimes 

 happens that several dark filaments lie in a single such 

 dumb-bell shaped body. Most of the corneous filaments (as 

 these filaments are described by Remak) exhibit abundant 

 short lateral thorn-shaped outgrowths ; only a few are smooth 

 superficially. Remak proceeds to say, that he once had an 

 opportunity of convincing himself upon a pale yellow trans- 

 parent corneous filament, one line in length, that it consisted 

 of a bundle of hollow fibrillse united with each other in the 

 direction of their length. 



