21 



Fiij. IT shows a piece of i)aper, a number of wliich when 

 gummed on to an egg, one over the other, and left to dry, 

 strengthen the shell in such a manner that the instruments above 

 described can be introduced through the aperture in the middle 

 and worked to the best advantage, and thus a fully formed em- 

 bryo may be cut up, and the pieces extracted through a very 

 moderately sized hole ; the number of thicknesses required de- 

 pends of course greatly upon the size of the egg, the length of 

 time it has been incubated, and the stoutness of the shell and the 

 paper. Five or six is the least number that it is safe to use. 



Fis. 17. 



Natural size. 



Each piece should be left to dry before the next is gummed on. 

 The slits in the margin cause them to set pretty smoothly, which 

 ■will be found very desirable ; the aperture in the middle of each 

 may be cut out first, or the whole series of layers may be drilled 

 through when the hole is made in the egg. For convenience 

 sake the papers may be prepared already gummed, and moist- 

 ened when put on (in the same way that adhesive postage labels 

 are used). Doubtless, patches of linen or cotton cloth would 

 answer equally well. When the operation is over, a slight ap- 

 plication of water (especially if warm), through the syringe, will 

 loosen them so that they can be easily removed, and they can be 

 separated from one another and dried to serve another time. 

 The size represented in the sketch, is that suital)Ie for an egg of 

 moderate dimension, such as that of a common fowl. 



Observations — The most effectual way of adopting this method 

 of emptying eggs, is by using very many layers of tldn paper and 

 plenty of thick gum, but this is of course the most tedious. 

 Nevertheless, it is quite worth the trouble in the case of really 

 rare specimens, and they will be none the worse for operating 

 upon from the delay of a few days, caused by waiting for the 



