PREFACE xiii 



Survey, both of mammals and birds, are extremely rich 

 in these intermediate or intergrading forms forms con- 

 necting many of the well marked types which were 

 formerly considered distinct species; and one day, when 

 the time can be spared from more strictly official work,* 

 the subject will be enriched by studies based upon this 

 material studies likely to form one of the most valuable 

 contributions of this generation to our knowledge of evo- 

 lution and we shall look back on the work of the Bi- 

 ological Survey as one of the most valuable achievements, 

 both practical and scientific, that ever had its origin in a 

 governmental department. 



In the way of field equipment, I had an open canvas 

 shelter, instead of a tent, with side wings so constructed 

 that, when pegged to the ground, they inclined outward 

 at an angle from the perpendicular, leaving extra space 

 for storing provisions. A detachable strip of canvas, a 

 foot wide, could be tied in front and sloped outward over 

 inclined poles. This prevented the rain from blowing in. 

 No one who loves camp life can prefer a tent to a shelter, 

 except in winter. The log fire which is always made before 

 the shelter, reflects warmth directly inside, so that one 

 can sit at ease and in enjoyment in all but the coldest 

 weather. A shelter is also more convenient to erect than 

 a tent. 



For sleeping, I had a coon-skin robe, eight feet square. 

 It weighed fourteen pounds. It keeps me warm enough 

 even in winter weather. A lynx-skin robe is better and 

 warmer, but more expensive. A caribou- or reindeer-skin 

 robe is the best of all. Equally warm, it is very much 

 lighter than either of the others. The wolf-skin robe is 



* Since the above was written Dr. Merriam has retired from his official posi- 

 tion for the purpose of devoting his time exclusively to scientific studies. A 

 large part of the results will appear in a comprehensive work on North Amer- 

 ican mammals. 



