628 SCIENTIFIC RECORD FOR 1884. 



Serrated Throat Appendages of Amia. — Tbe eo-callcd "mnd-fisb" or 

 "Inwyei" {Amia calva) of oiir Western aud Sontbern lakes and livers, is 

 especially interesting^ to tbeuiorpbolojiist on acconutof tbe peculiarities 

 of structure aud the babits coino-ideut tberewitb whicb it exhibits, and 

 also, more especially, from tbe fact of its being interraediate between 

 tbe old-fasbioned and tbe new-fasbioned fisbes. One of tbe peculiari- 

 ties of this lisb is tbe existence of " serrated appendages" or " flagella" 

 beneath ibe throat, which are attached by their bases to tbe lateral as- 

 pect of tbe sterno byoid muscles. Experiments bave been made, under 

 the direction of Prof. K. llamsey Wright, of University College, Toronto, 

 to elucidate the i)hysiology of these appendages. His specimens of 

 Anfia, "after being in captivity for some time, became very sluggish, 

 aud hardly any movements of res])iration could be detected. Alter tbe 

 fish bad been removed for a little out of tbe water, however, and then 

 returned to it, tbe movements were sufficiently active to disclose tbe fol- 

 lowing facts: 



'• During tbe enlargement and filling of tbe cavity of the mouth, tbe 

 posterior flexible (and muscular) border of the gill-opening is tightly 

 applied to tbe soil parts behind tbe gill-opening. When tbe monthcav- 

 ity is quite full, tbe mouth closes, tbe muscular border of tbe gill cover 

 releases its sucker-like bold of the soft parts, and tbe water is driven 

 out by tbe contraction of tbe walls of the mouth-cavity." {Science, v. 

 4, p. 511.) 



Bevelojwient of the common American Catfish. — Mr. John A. Eyder 

 has published tbe results of an investigation into tbe embryology of 

 a common American cattish, tbe Amiurus alhidus. The eggs of this 

 species are laid in a large depressed mass, and are adherent together 

 and to tbe object upon whicb they are laid. They are about one-eighth 

 inch in diameter and batch in about six days, when tbe water is of the 

 temperature usually prevalent during tbe breeding season of tbe species, 

 whicb, about Washington, is in July. The male, after the eggs are laid, 

 faithfully guards tbe eggs, hovering over them, and fanning tbe mass 

 of ova with his lower fins, apparently for the purpose of forcing water 

 through them. 



Each egg is covered bj' two envelopes, an inner true zona radiata 

 and an outer elastic adhesive lamina, which is raised up from the inner 

 one upon a series of columns consisting of tbe elastic substance. It 

 thus results that a space is formed between the inner and outer envel- 

 opes of the egg, which is filled with water. Tbe outer elastic envelope 

 permits the male to make comparatively violent movements while re- 

 newing the water over the ova without detaching them from one 

 another or from the objects to which they are affixed. Indeed, the elas- 

 ticity of this outer membrane is surprisingly extensive in tbe living ova. 



On tbe second day tbe barbels appear in blunt processes, thus early 

 Refining the order to which the embryos appertain. They arise at the 



