u 



same or nearly allied species, should never be so marked that 

 confusion can possibly arise. It is desirable to mark temporarily 

 with a pencil each egg as it is obtained ; but the permanent 

 inscription, which should always be in ink, should be deferred 

 until after the egg has been emptied. The number terminating 

 the inscription in all cases referring to the page of the collector's 

 note-book, wherein full details will be found, and the words or 

 letters preceding the number serving to distinguish between dif- 

 ferent collectors, no two of whom ought to employ the same. 

 (The initial letter of the collector's name, prefixed to the num- 

 ber, will often be sufficient.) 



PREPAEATION OF SPECIMENS. 



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

 hole, which should be drilled in the side with such an instrument 

 as shown in the sketches (Jigs. 1, 2, and 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 opera- 

 tion 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. 14), by which 

 means not only is the removal of the contents, but also the sub- 

 sequent cleansing of the specimen, facilitated. The small end of 

 a blowpipe (Jigs. 4 and 5) should then be introduced, while the 

 other extremity is applied to the mouth, and blown through, at 

 Jirst very gently. If the embryo is found to be moderately de- 

 veloped, a stream of water should be introduced by means of a 

 syringe (Jig. 7), and the egg then gently shaken, after which the 

 blowpipe may be again resorted to, until by the ultimate use of 

 both instruments, aided by scissors (Jigs. 8 and 9), hooks (Jigs. 

 10, 11, and 12), knives (figs. 13, 14, and 15), and forceps (fig. 



' The great object to be attained is the formation of a circular hole 

 with smooth edijes. Collectors not having such a drill as is here recom- 

 mended, will find a common nail or a three-cornered needle a useful 

 substitute, but they must be used with extreme care. 



