156 NESTS AND EGGS OF NORTH AMERICA.N BIRDS. 



a number or other mark showing the locality, date, collector, and 

 supposed species, as well as relationship to an embryo removed, or to 

 any portion of the parent preserved. It will in most cases be best 

 to attach the same number to nest, eggs, embryo, and parent 

 belonging together. This mark may be made neatly on the eggs, 

 itself with ink and a quill pen, or on a label carefully packed with 

 them. A record book showing what has been taken and preserved, 

 with dates and explanatory remarks, should always be kept. 



In making the apertures in eggs that have peculiar markings, care 

 should be taken to select some inconspicuous spot that will leave the 

 pattern of coloration undisturbed. Eggs that are cracked may be 

 greatly strengthened by pasting tissue or other thin paper along the 

 line of injury, or what is easier, and in most cases even better, by brush- 

 ing collodion along and over the cracks. It is often well to cover the 

 punctures or holes cut out, especially if large, with thin paper or gold- 

 beaters' skin. If a piece be removed, it can usually be easily replaced 

 and kept in by pasting thin paper over it and the line of separation, 

 or around the latter. 



Notwithstanding the apparent fragility of eggs, a very little expe- 

 rience will enable any one to empty them of their contents with great 

 ease and safety. The principal accident to be guarded against is that 

 of crushing the egg by too great pressure between the fingers ; these 

 should be applied so as to barely hold the egg, and no more. If the 

 operation of emptying be performed over a full basin of water, the 

 occasional dropping of the egg from the finger into the water will be 

 attended with no harm. 



To pack eggs for transportation, each one should be wrapped in a 

 light envelope of cotton and laid down in layers separated by strata 

 of cotton. They should be kept in rather small boxes of wood, or if 

 pasteboard be used, these should always be transmitted in wooden 

 boxes, as the eggs are thereby less likely to be broken by a sudden jar 

 or shock. If the nest is sent along, it may contain the eggs belong- 

 ing to it, each one wrapped in cotton, and the vacancy of the nest filled 

 with the same or other light elastic material. It will be well to pin 

 or tie up each nest in paper to keep it secure, and to prevent entangling 

 of the materials when several are laid together. A temporary box 

 may often be readily constructed of pasteboard, to contain the more 

 delicate or valuable ones. 



Whenever practicable, the embryos or young found in the egg 

 should be carefully preserved in alcohol, great care being of course 

 taken to mark the specimens properly. The better plan will be to 

 keep each set in a small bottle or vial, and a slip of stiff paper or 

 parchment placed inside with the number or name. Whenever the 

 abundance of the eggs will warrant it, a large number with the 

 young in different degrees of development, even as many as fifty of a 

 kind, should be secured. The embryos in this case need not be re- 

 moved from the egg, which should, however, be cracked at the blunt 

 end to facilitate the entrance of the spirit. Researches at present in 

 progress relating to the embryology of birds promise results of the 

 highest interest in reference to ornithological classification. 



