44 



BIRDS-NESTING. 



enclosed circle of shell. This must be done with 

 great caution, for egg-shells grow more brittle to- 

 ward the time of hatching. The hole being drilled, 

 the lining membrane 

 should be cleared away 

 from the orifice with a 

 penknife . Well - f o r m e d 

 embryos cannot be got 

 through any hole that can 

 be made in the shell, and 

 it must not be tried — there 

 is every probability of ru- 

 ining the specimen ; they 

 must be extracted piece- 

 meal. First, a stream of 

 water should be introduced 

 by means of a syringe, 

 and the egg then gently 

 shaken, after which the 

 blow-pipe may again be 

 resorted to, until hy the 

 ultimate use of both in- 

 struments, aided by minia- 

 ture scissors, hooks, knives and forceps, the embryo 

 is cut to pieces and completely removed. 



Some types of the forms of these miniature oosur- 

 gical instruments, as I may be pardoned for calling 



Fig. 7. 



