in the Animal Kingdom. 363 



said before, perform very different functions also. Hence a po- 

 sitive, in addition to a negative source of error. 



But what other course could naturalists have taken ? Truly 

 none : their " circumstance" allowed no other. It is only now 

 that a way is beginning to be opened, by which it may by and 

 by be possible to proceed in an opposite direction ; viz. from 

 trunk to branches and to twigs. 



This, if ever accomplished, must be by means of the History 

 of Development or Embryology^ both human and comparative ; 

 a science almost new, and regarding which, there prevails in this 

 country the profoundest ignorance and indifference. The French 

 are in advance of us ; but it is to German enterprise, industry, 

 and perseverance, that we are indebted for almost every fact 

 known to us on this subject ; at least of those brought to light 

 in recent times.* It is to be hoped, however, that ere long this 

 science will begin to obtain, even among ourselves, some degree 

 of the attention which its importance claims.^ 



If these remarks are not uncalled for, in reference to nomencla- 

 ture and classification, they will not perhaps be deemed unwor- 

 thy of consideration, when applied to a science, in the study of 

 which, nomenclature and classification are but means. But in- 

 dependently of these, does it require much penetration to dis- 

 cern, whether it is easier, in the study of any science, first to 

 commit to memory isolated facts, and then proceed to arrange 

 them ; or, having first become acquainted with general princi- 

 ples, to trace their applications? In other words, having first 



* When St Hilaire proclaimed in France the principle, that zoological re- 

 search can have no solid basis but in anatomy, and that it is not the organa 

 of the functions in their totality, but the materials constituting these organs, 

 between which, resemblances are to be sought for, he advanced a most es- 

 sential step : yet there was still wanting, more regard to Embryology. 



t Dr Allen Thomson's excellent paper (see vol. ix. and x. of this Journal) 

 we have already noticed. 



The recent appearance, too, of a " Sketch of the Comparative Anatomy of 

 the Nervous System, with Remarks on its Development in the Human Em- 

 bryo" by John Anderson, M.E.S., 4to, 1837, shews that there are grounds 

 for such an expectation as is expressed above. We have only just glanced 

 the volume through, but seen enough to say, that it contains many valuable 

 and well-arranged facts, admirably calculated to illustrate the doctrines of the 

 great Meckel and others, published in Germany so many years ago. Had we 

 read this essay before writing the present memoir, some of the facts it con- 

 tains might have been adduced by way of illustration. 



