THE ART OP PEESERVING BIRDS. 27 



bill horizontal with the back or bottom of the rounded 

 space, with the culmen (Plate IV., Fig. 1, d) nearly touch- 

 ing the paper. The skin must remain in this position 

 without being disturbed untO. perfectly dry, which in very 

 warm weather, with small birds, will be in about twenty- 

 four hours. 



If this corrugated- board cannot be procured, the skin 

 may be placed on its back upon a flat surface, with a 

 little cotton on each side of it to prevent its getting dis- 

 placed. This is what is technically termed "a skin" 

 (Fig. 3), and this method of making them is the best I 

 have ever seen practised, and one that I have used for 

 years as being the most expedient. The skins so made 

 are less liable to injury, being stronger than some others, 

 and are also very easily mounted. I have made in a 

 single day, in the manner described, fifty skins, and with 

 practice almost any one will be able to do the same ; ten 

 minutes being ample time for each, including the meas- 

 uring. 



Before the skin is placed upon the board, it should be 

 labelled (Fig. 3, $) with a number corresponding to the 

 one placed upon the slip of paper containing the meas- 

 urements, etc., marked also for the sex of the bird, which 

 is done by using for the male the sign of the planet 

 Mars, thus $ ; for the female the sign of the planet 

 Venus is used, thus 9 . These signs are used by natural- 

 ists throughout the scientific world, and it is best to be- 

 come accustomed to them. 



Determining the Sex. — The sex of the bird is determined, 

 not by the plumage, which will sometimes set the student 

 at fault by its changes, and should never he trusted in de- 

 termining the sex, but by dissection, as follows : Take the 

 body of the bird after it has been removed, and cut with 

 the scalpel through the ribs (Plate X. A) on the sides 

 of the abdomen, thereby exposing the intestines; raise 



