342 FRANCIS H. HERRICK 



there is as to the treatment of materials when obtained. As 

 a rule there is no fussing with the substance chosen though of 

 course attempts to dislodge things often fail. The business 

 throughout appears to be conducted with the utmost prompt- 

 ness and dispatch, with no suggestion of indecision or delibera- 

 tion; indeed, it often seems as if every movement were necessary 

 and predetermined. This, I say is the general impression con- 

 veyed after many hours of close watching; on the other hand, 

 a robin will now and then make a tentative stab at the ground 

 with no result, or having taken a weed or btmch of grass, will 

 reject it, but this seldom happens, and may be determined 

 by the influence of the male at the moment, who has perhaps 

 moved to another point, or by some other element in the situ- 

 ation, such as the appearance of other birds. 



It should not be infen-ed that there are no di\'ersions or dis- 

 tractions while material is being gathered, for there are many; 

 now the work progresses uniformly and rapidly; then it will 

 vary or lag. These delays, in my opinion, are mainly due, 

 to other causes than failure to search in the right places or to 

 discover the proper substances. The effervescent character of the 

 most potent instincts in birds, as in mammals, is very marked 

 at all times and may be witnessed in every phase of the repro- 

 ductive cycle. Thus, a bird when its young are assailed, and 

 after it has displayed great pugnacity, and sounded its most 

 emphatic alarms, will suddenly quiet down and calmly preen 

 its feathers, as if nothing had happened, before another out- 

 burst ensues. We haA'e seen that in nest building the aim to 

 protect the site by concealment and secrecy is predominant, 

 and delays in gathering the materials may be caused by the 

 inhibiting presence of other birds, or by the distraction of food, 

 which the builders naturally find in their customary methods 

 of search. Hunger undoubtedly checks nest building at many 

 points, and may be the cause of much of the delay observed. 



In some cases the male will pick and dab at material as if 

 in imitation of the female or in satisfaction of a feebly developed 

 instinct, but in this instance, as we have remarked, the cock 

 brought nothing to the site. In returning to the nest the female 

 starts first and usually keeps the lead, the cock following close 

 behind or abreast as before, he going to the place where he 

 stands guard, and she to a point on the limb which habit soon 



