Re: pores

[NEIL CLARK <NCLARK@museum.gla.ac.uk>]

> Neil Clark asked: 
> 
>  Does anyone know whether there is a 
> >simple way of determining how many pores reach the outer 
surface if 
> >it is damaged?
> 
> Yes, you make what is called a tangential section.  See the article 
on 
> preparation of eggshell for study by Betty Quinn in the Pat Leiggi 
and 
> Peter May "Vertebrate Preparation" book by Cambridge University 
Press 
> (1994).
> 

Yes, but if you do a tangential slice, you still have the problem of not 
knowing how many of the pores actually reach the surface of the egg. 
 Many of the pores do not reach the surface as they terminate 
beneath the outer layer.  In tangential section I have counted over 
2,000 pores per sq cm.  I am presuming that the outer layer is sawn 
off during tangential section preparation, but also if the surface is 
worn then the results would also be spurious.   I think that for 
physiological studies you would need to use the number of pores 
reaching the outer surface?

Neil


Neil Clark
Curator of Palaeontology
Hunterian Museum
University of Glasgow
email: NCLARK@museum.gla.ac.uk

Mountains are found in erogenous zones.
(Geological Howlers - ed. WDI Rolfe)