7196 Birds, 



Figs. 15 and 16 represent a penknife and scalpel with elongated 

 blades or shafts, to admit of their being introduced into the egg to cut 

 up the embryo. Fig. 15 is also, perhaps, the best instrument with 

 which to remove the lining membrane from the hole. This is done 

 by inserting the blade perpendicularly, and slightly scraping the edge 

 of the hole as soon as it is drilled. 



Fig. 17 represents a forceps for extracting the pieces of the embryo 

 when cut up. The spring should not be too lively, as its resiliency 

 may occasion breakage. The grasping surfaces should be roughened 

 to prevent the pieces slipping.* 



5. Preparation of Specimens. 



Eggs are emptied with the least amount of trouble at one hole,t 

 which should be made at the side of the specimens, as shown in the 

 annexed engravings (figs. 18 and 19), with one of the drills already 

 described (figs. 1, 2, 3). The hole should of course be proportioned to the 

 size of the egg and the amount of incubation it has undergone. Eggs 

 that are hard sat upon are more easily blown by being kept a few days, 

 but the operation must not be deferred too long or they are apt to 

 burst violently immediately on being punctured, though this may be 

 avoided by holding them under water while the first incision is made. 

 The hole being drilled, the lining membrane should be cleared away 

 from the orifice with a penknife (fig. 15), by which means not only is 

 the removal of the contents, but also the subsequent cleansing of the 



* Most, if not all, of the implements here described may be obtained of any 

 surgical-instrument maker. I have pleasure in mentioning the name of Mr. J. Evrard, 

 of 35, Charles Street, Middlesex Hospital, as that of the workman who for some years 

 past has supplied several of my friends and myself. He fits up neat and convenient 

 pocket-cases with a set of all the most useful tools for egg-blowing and bird-skinning. 

 Mr. David Mackenzie, of 58, South Bridge, Edinburgh, I have been informed, furnishes 

 drills, blowpipes, &c., and at a most reasonable rate. I believe that the Smithsonian 

 Institution of Washington will, with its usual liberality, equip any of its correspondents 

 in America according to their requirements. 



\ Those who may still prefer to blow eggs by means of 

 two holes are particularly requested not to make them at 

 the ends of the eggs, nor at opposite sides, but on the same 

 side (fig. 20). Tn this case the hole nearest the smaller 

 end of the egg should be the smallest, and the contents 

 blown out at the other. If the holes are made at the ends 

 of the eggs it not only very much injures their appearance p. 



as cabinet specimens, but also prevents their exact dimen- 

 sions from being ascertained accurately; and if they are made at opposite sides the 

 extent of the " show surface " is thereby lessened. 



