40 Professor Owen on the [Feb. 9, 



sexes derived their sustenance from the mother's milk. Its growth 

 proceeded and was almost completed before the sexual development 

 had advanced so as to establish those differences of habits, of force, 

 of muscular exercises, which afterwards characterise the two sexes. 

 The whole crown of the great canine is, in fact, calcified before it 

 cuts the gum or displaces its small deciduous predecessor ; the 

 weapon is prepared prior to the development of the forces by which 

 it is to be wielded ; it is therefore a structure fore-ordained, a 

 predetermined character of the chimpanzee, by which it is made 

 physically superior to man ; and one can as little conceive its 

 development to be a result of external stimulus, or as being influ- 

 enced by the muscular actions, as the development of the stomach, 

 the testes, or the ovaria. 



The two external divergent fangs of the premolar teeth, and 

 the slighter modifications of the crowns of the molars and pre- 

 molars, appear likewise from the actual results of observation to be 

 equally predetermined and non-modifiable characters. 



No known cause of change productive of varieties of mammalian 

 species could operate in altering the size, the shape, or the con- 

 nexions of the premaxillary bones, which so remarkably distinguish 

 the great troglodytes gorilla, not from man only, but from all other 

 anthropoid apes. We know as little the conditions which protract 

 the period of the obliteration of the sutures of the premaxillary 

 bones in the tr. gorilla beyond the period at which they disappear in 

 the tr. niger, as we do those that cause them to disappear in man 

 earlier than they do even in the smaller species of chimpanzee. 



There is not, in fact, any other character than those founded 

 upon the developments of bone for the attachment of muscles, which 

 is known to be subject to change through the operation of external 

 causes ; nine-tenths, therefore, of the differences, especially those very 

 striking ones manifested by the pelvis and pelvic extremities, which 

 the Professor had cited in memoirs on the subject, published in the 

 " Zoological Transactions,'* as distinguishing the great chimpanzee 

 from the human species, must stand in contravention of the hypo- 

 thesis of transmutation and progressive development, until the 

 supporters of that hypothesis are enabled to adduce the facts and 

 cases which demonstrate the conditions of the modifications of such 

 characters. 



If the consideration of the cranial and dental characters of the 

 troglodytes gorilla has led legitimately to the conclusion that it is 

 specifically distinct from the troglodytes niger, the hiatus is still 

 greater that divides it from the human species, between the extremes! 

 varieties of which there is no osteological and dental distinction 

 which can be compared to that manifested by the shorter pre- 

 maxillaries and larger incisors of the troglodytes niger as compared 

 with the tr. gorilla. 



The analogy which the establishment of the second and more 

 formidable species of chimpanzee in Africa has brought to light 



