SEC. IX COLLECTION OF NESTS AND EGGS 79 



hole may be drilled, as before, but it must be larger ; and as the 

 drill is apt to split a shell after it has bored beyond a certain size 

 of hole, it is often well to prick, with a fine needle, a circular series 

 of minute holes almost touching, and then remove the enclosed 

 circle of shell. This must be very carefully done, or the needle will 

 indent or crack the shell, which, it must be remembered, grows 

 more brittle towards the time of hatching. Well-formed embryos 

 cannot be got bodily through any hole that can be made in an egg ; 

 they must be extracted piecemeal. They may be cut to pieces with 

 the slender scissors introduced through the hole, and the fragments 

 be picked out with the forceps, hooked out, or blown out. No 

 embryo should be forced through a hole too small ; there is every 

 probability that the shell will burst at the critical moment. Addled 

 eggs, the contents of which are thickened or hardened, offer some 

 difficulty, to overcome which persistent syringing and repeated 

 rinsing are required ; or it may be necessary to fill them with water, 

 and set them away for such length of time that the contents dis- 

 solve by maceration ; carbonate of soda is said to hasten the solution ; 

 the process may be repeated as often as may be necessary. In no event 

 must any of the animal contents be suffered to remain in the shell. 

 When emptied and rinsed, eggs should be gently wiped dry, and set 

 hole downward on blotting-paper to drain.^ Broken eggs may beneatly 

 mended, sometimes with a film of collodion, or a bit of tissue paper 

 and paste, or the edges may be simply stuck together with any 

 adhesive substance. Even when fragmentary a rare egg is worth 

 preserving. Eggs should ordinarily be left empty ; indeed, the 

 only case in which any filling is admissible is that of a defective 



^ Reinforcing the Eggshell before Blowing. — Fig. 8 " shows a piece of paper, a 

 number of whicli, -when gummed on to an egg, one over the other, and left to dry, 

 strengthen the shell in such a manner that the instruments ahove described can be 

 introduced through the aperture in the middle and worked to the best advantage, and 

 thus a fully formed embryo may be cut up, and the pieces 

 extracted, through a very moderately sized hole , the number 

 of thicknesses required depends, 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. 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 Tig. 8.— Nat. size, 

 gummed, and moistened 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 application 

 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 suitable for an egg of moder- 

 ate dimension, such as that of a common fowl. The most efi'ectual way of adopting 



