BLOWING EGGS. 103 



through the blow-pipe, or with the syringe. Blowing eggs is 

 a rather fatiguing process — more so than it might seem ; the 

 cheek muscles soon tire, and the operator actually becomes 

 "blown" himself before long. The operation had better be 

 done over a basin of water, both to receive the contents, and 

 to catch the egg if it slip from the fingers. The membrane 

 lining the shell should be removed if possible. It may be 

 seized by the edge around the hole, with the forceps, and 

 drawn out, or picked out with a bent pin. Eggs that have 

 been incubated of course offer difficulty, in proportion to the 

 size of the embryo. The 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 may 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 foveed through a hole too 

 small; there is every probability that the shell will burst at 

 the critical moment. When emptied and rinsed, eggs should 

 be gently wiped dry, and set hole downward on blotting paper 

 to drain. Broken eggs may be neatly metided, 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 sub- 

 stance. Even when fragmentary a rare egg is worth preserv- 

 ing. Eggs should ordinarily be left empty ; indeed, the only 

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

 specimen to which some slight solidity can be imparted with 

 cotton. It is unnecessary even to close up the hole. It is 

 best, on all accounts, to keep eggs in sets, a " set" being the 

 natural clutch, or whatever less number were taken from a 

 nest. The most scrupulous attention must be paid to accu- 



