turn buoyancy causes : 



.0 "breatl . iber" of F. -arise , Long 



this rotation persists I can not say, but certainly until 

 after the closure o . - . Rathke ( '37) first 



this in the eggs of E 

 as best I can make it out, - aterial co- 



lter or in air, which fills the " ?wisehenraum " re fen 



- Pilling this space 



in _3_» floridai . it es not coagulate in water, air, or in 

 any of the fixing fluids I have used. It might be well to 

 here that this rotation of - is not a new phen - 



enon, j Ziegler !' ' 



vrliest preservations of eggs 

 disc were made foufr to five hours after t . had been 



place.,, i , . tole to descrj , ; act- 



ions its formation. In any cat:, however, I could not hope 



a classic paper of Agassiz 

 on Ctenolabrus , or to the more recent memoir of Behrens on 

 the Brook Trout, Since, I preserved eggs at int< rvals of 

 from five to twenty- five hours, I have sections which show 

 the progressive degeneration of the blastodisc. So far as 

 I know, this Has never been shoi tence it may ue of 



