MODES OF STUDYING ANATOMY. 285 



It might well be thought that the ways in which the philosophical 

 investigation of animal organization may be carried out, were exhausted 

 in the monographical or anthropotomical, organical, embryological, zoo- 

 logical and homological methods just defined. But there is yet another 

 method. 



I do not allude to the microscopical mode of research : that is only 

 a more refined method of the scrutiny of animal parts, and has now 

 become an essential one, whether we investigate the structure of an 

 organ or of an organism, — whether we are tracing the modifications of 

 the heart, e. g., in a succession of animals, or the combination of the 

 puLsatile and other organs in one minute animal. It is true, that, as 

 the high powers of the microscope can only be brought to bear on minute 

 particles, they have been for the most part applied to the constituent 

 parts of an organ, the tissues, as they are termed, whence the term 

 * Histology,' now commonly applied to microscopic anatomy. 



But this more refined mode of research, so successfully and system- 

 atically pursued within these walls by my esteemed colleague, Professor 

 Quekett, must be superadded to the ordinary procedures of dissection, 

 whether we pursue an absolute anatomy of one species, or enter upon 

 the anatomy of animals generally, by either of the routes, organically, 

 embryologically, or zoologically, which I have just denned. Histology 

 is a minuter mode of anatomizing, but is not a distinct kind of compara- 

 tive inquiry. Beckoning it, however, as a sixth kind, what, then, it 

 may be asked, is the seventh way in which the highest generalizations 

 in anatomical science may be aimed at ? My reply is, by pursuing inves- 

 tigations beyond the animals that are, to those that liave been. 



Let us assume it to be a truth that the actually existing animal 

 creation forms but a small proportion of that which has lived and ener- 

 gized during former periods on this planet. 



Each year brings more evidence of this truth, and narrows the pro- 

 portion which the present zoological series bears to the past, — the living 

 to the extinct creations ! 



If all the successive races of beings that have peopled, at successive 

 periods, the same globe be the work of one and the same Creative force, 

 can we hope to gain a due insight into the laws according to which 

 that force has operated in their introduction, by limiting our investiga- 

 tions to the residuary groups of beings that characterize the present epoch? 

 As well might we flatter ourselves that we had an adequate notion of 

 anatomy from the results of assiduous anthropotomy, as that we could 

 arrive at the highest facts in the philosophy of animal structures without 

 having first observed and compared all the structures at our command. 

 The soundness of the Baconian principles of induction are too firmly 



