If proper conditions were afforded to keep a pair of kulus in training for some years, it is difficult to say what they might not be taught. They are not only apt in learning what they are taught, but they are well disposed and can apply their accomplishment to some useful end. We cannot say to what extent they may be able to apply what they learn from man, because the necessity of using such knowledge is removed by the attention given to them. CHAPTER XX The Gorilla--His Habitat--Skeleton--Skull--Color--Structural Peculiarities In the order of nature the gorilla occupies the second place below man. His habitat is the lowlands of tropical West Africa, and it is confined to very narrow limits. The vague lines which bound his realm cannot be defined with absolute precision, but those generally given in books that treat of him are not correct. If he ever occupied any part of the coast north of the equator, he has long since become extinct in that part; but there is nothing to show that he ever did exist there. So far as I have been able to trace the lines that define the extent of his native haunts, they appear to confine him to the low delta country lying between the equator and the Loango valley along the coast, and reaching eastward to the interior--an average distance of less than one hundred miles. The eastern boundary is very irregular. The extreme limit on the north side is about the Gaboon River, eastward to the foothills of the Crystal Mountains; thence southward to the Ogowé River to the vicinity of the mouth of the Nguni; thence up that river twenty or thirty miles; thence by a zigzag line along the western base of the dividing lands between the Congo basin and the Atlantic watershed, to the head-waters of the Chi Loango River, and with that valley to the coast. Beyond these lines I have found no reliable trace of him, and along this boundary only now and then is he found, except along the coast. I have seen two adult skulls and two infant skulls of the gorilla that were brought by Mr. Wm. S. Cherry from the Kisanga valley, which lies on the north side of the middle Congo, into which the Kisanga River flows. The skulls are the only evidence I have found of this ape existing so far eastward; but they were said to have come from that part of the valley lying directly under the equator. Mr. Cherry himself did not collect them. He secured them from natives, and he does not claim to have seen any of those apes alive.