OBSERVATIONS ON A SPECIMEN OF " SULA BASSANA." 331 



Tarious parts of nature, the circles of three or five groups, with their 

 sub-divisions and their analogies, in which all truths respecting rela- 

 tionship were supposed to be contained. 



Individually, — though deeply interested in such inquiries, — I was 

 never led to adopt the quinary or any kindred system. I was often 

 forcibly struck by the apparent truth and beauty of the combinatioas 

 produced ; but I also fancied I met with some manifest errors, some 

 forcing of objects into a place, and some far-fetched analogies. I was, 

 besides, much influenced by general arguments on the subject, which, 

 whatever be their true weight, seem to have prevailed with the great 

 majority of naturalists. And yet, after twelve years of constant at- 

 tention to the formation, arrangement, and care of museums, during 

 which it has been a special object with me to make the specimens 

 instructive, by placing them in natural groups, I find myself com- 

 pelled by my experience to the recognition of the very kind of collec- 

 tions of families usually five in number, and conveniently represented 

 as forming a circle, for which Mr. Swainson contended, and I find it 

 impossible lo resist being impressed by the remarkable analogies of 

 corresponding groups belonging to different circles. Reflecting much 

 on the nature of these relations, I have gradually formed a theory 

 which seems to me to connect all the facts, and to afford all the ex- 

 planation of them which we can expect. I conceive that every dis- 

 tinct type of animal structure is capable of being worked out with a 

 larger proportional development of the organs of sense and motion ; 

 or, on the other hand, of those of nutrition : and under the former 

 head the development may take the direction of power and ferocity, 

 of greater elevation, and completeness of structure ; or that of grace 

 and activity, with general adaptation, where it is at all consistent 

 with the plan of nature, to an aerial or arboreal life. Under the 

 second head, the higher form of peculiarly nutritive development 

 will be known by a well-balanced figure, with a somewhat full habit 

 of body, comparativelj' quiet and gentle manners, in lower forms 

 approaching sluggishness, and the use chiefly of food which needs 

 not to be obtained by violence or energetic effort. But under this 

 general head there are two other remarkable modifications : one for 

 anomalous — often in some way elongated — forms ; and one for the 

 lowest structure consistent with the general type, very often connected 

 with aquatic life. These are to be understood as tendencies of deve- 

 lopment, and we affirm that they include all the distinct tendencies 



