1912] Miller: Pacific Coast Avian Palaeontology 77 
The prevailing conditions also led to a greatly distorted 
relation between predaceous and non-predaceous species in point 
of numbers. While removing a single femur of Paramylodon 
there were found touching it three complete skulls of Canis 
indianensis, and even this proportion of three to one is much 
too small to represent the facts truthfully. In a collection of 
bird remains made by the writer the number of specimens of 
Aquila exceeds the number representing all the non-raptorial 
species combined, while fifty-six per cent of the species recorded 
are predatory. 
The cessation of struggling on the part of the entrapped 
animal did not end its services as trap bait. Some forms which 
normally seek an active prey, e.g., Canis and Aquila, may on 
occasion resort to carrion. <A decrepit wolf or a hungry eagle 
may not infreqently thus supply the demands of necessity. The 
odors emanating from these pits where freshly excavated are, 
to human nostrils, strongly suggestive of carrion. Gases exhaled 
by animal bodies submerged in the plastic mass would aecen- 
tuate this olfactory effect to such a degree as probably to attract 
carrion feeders. Was this influence also felt by birds? Dar- 
win’s well-known experiments on Andean condors kept in cap- 
tivity have long been accepted as proving that the vultures do 
not employ the olfactory sense in the perception of food. How- 
ever, the experiences of later naturalists with Cathartes, which 
is often caught in wolf-traps with concealed bait, leads us to 
emphasize the fact that Darwin was experimenting with birds in 
captivity which had been fed perhaps from early youth in more 
or less regular fashion. We must at least concede it possible 
that the abundant vulture remains in the asphalt are the result 
in part of this factor of odor in attracting them to the locality. 
