IN RELATION TO ORGANISED BEINGS. 43 



should not willingly give up the belief that the brain of man is in some 

 way superior to that of monkeys, and that he ought to hold a preemi- 

 ment position in a truly natural view of the animal kingdom. It is 

 very dangerous to rely for our principles of classification on characters 

 drawn from one function, or one mode of viewing animal structures, if 

 we are seeking a truly natural system. "We, of course, want facts col- 

 lected in relation to every part of structure, and no well-authenticated 

 facts are lost to the enlightened naturalist ; but it is always to be 

 recollected that reliance on one set of organs will mislead us if it be not 

 the most important not yet otherwise employed, and that we are very 

 liable to mistake adaptive modifications of structure for great organic 

 differences. Even embryology, high as is its degree of importance, 

 cannot safely be trusted too far, since it has led one so profoundly 

 acquainted with its facts, and so skilful in the application of principles 

 as Agassiz, to cut up into distinct classes the eminently natural group 

 of fishes. His observations may be true and valuable, and may assist 

 in determining the subdivisions of the class; but I cannot but think that 

 he exaggerates their proper influence when he multiplies on their 

 account the classes under the vertebriate type. 



Mr. Dana's principle of Cephalisation, as a basis of classification, 

 may perhaps be liable to a similar objection. No doubt it embodies 

 important truth, and real assistance may be drawn from it in deter- 

 mining the highest structures under each type, but I cannot help 

 thinking that it has already shown itself liable to abuse, and that so 

 far as it is good, it only confirms what is obtained from other sources.* 

 Very ingenious and noteworthy attempts have been made to arrange 

 mammals according to the mode of placentation. The facts obtained 

 are a valuable addition to science, and might be very useful in deter- 

 mining in a doubtful case to which of two groups an animal ought to 

 be referred, but I must think it a great error, in that highest class of 

 the highest sub-kingdom, which especially represents the development 

 of the organs of sense, and the faculties which most elevate a being, 

 to look to the reproductive system, the lowest of the separate functions 



* I cannot suppress the expression of a hope that, should this be deemed the 

 best application of the facts, upon which it has served strongly to fix attention, 

 respecting the concentralioa of important organs in the anterior portion of the body 

 in the higher structures under each type, the expounders of tlie system will at 

 least avoid certain very barbarous terminology, with whicli its distinguished 

 author has burthened it. 



