The Mental Life of Monkeys and Apes: A Study of Ideational Behavior

permanent provision for the thorough study of all aspects of the lives of these animals. The values of these interests and of the tasks which they have led me to undertake a

n welfare than my experimental study of ideational behavior, I give the latter first place in this report, reserving for the concluding section an account of the situation regarding our knowledg

station and experimenting with monkeys and apes. First of all, the interruption of my academic duties by sabbatical leave gave me free time. But in

of co?perative work instead of the establishing of an American station. This invitation I gratefully accepted with the expectation of spending the greater part of the year 1915 on the island of Tenerife. But the outbreak of the war rendered my plan impracticable, while at the same time destroying all reasonable ground for hope of profitable co?peration with the Germans in the study of the anthropoids. In August, 1915, Doctor Rothmann died. Presumably, the station still exists

bibliography at

, Doctor G. V. Hamilton, to make use of his collection of animals and laboratory at Montecito, California, during my leave of absence from Harvard. This invitation I most gladly accepted, and in February,

dness nor make satisfactory acknowledgment here of his generous aid. Thanks to his sympathetic interest and to the courtesy of the McCormick family on whose estate the laboratory was located, my work was done under wholly delightful conditions, and with assistance

. All were thoroughly acclimated, having lived in Montecito either from birth or for several years. The orang utan was a young specimen of Pongo pygmaeus Hoppius obtained from a San Francisco dealer in October, 1914 for my use. His age at that time, as judged by his size and the presence of milk teeth, was not more than five years. So fa

sting attitudes. In plate I, figure 1, Julius appears immediately behind the laboratory seated on a rock, against a background of live oaks. This figure gives one an excellent idea of the immediate environment of the laboratory. Figure 2 of the same plate is a portrait of Julius taken in the latter part of August. By reason

ually preparing for an attack on another monkey behind the wire screen. Figure 7 of this plate indicates Skirrl in an interesting attitude of attention and w

TION OF

utan, Julius, re

ius walking a

-P. rhesu

hing his jaws (yawn?)

.-P. iru

rrl using ham

-Skirrl u

oughly understands them than any other observer of whom I have knowledge. Much to my regret and embarrassment in connection with the present report, he has thus far published only a small portion of his data (Hamilton, 1911, 1914). In his most recent paper on "A study of sexual tendencies in monkeys and baboons," he has g

nimals in

hecus irus.

hesus. Youn

hesus. Female. Bo

sus. Young a

P. irus. A

irus (?).

esus. Female. Bo

P. irus. A

irus. Ad

ung adult male. B

aeus. Male. Age, 4

o the special needs of my experiments. The laboratory was finally located and built in a grove of live oaks. From the front it is well shown by figure 10 of plate III,

ound plan of Montecito labor

tus was installed; B, E, additional rooms for research; D, store room and s

construction was throughout simple, everything was convenient and so planned as to expedite my experimental work. The large room A, adjoining the cages, was used exclusively for an experimental study o

mall cage was six, by six, by twelve feet deep, while the large compartment into which each