190 PROCEEDINGS OF THE ACADEMY OF [April, 



aad the present contribution is in the main a discussion of the 

 values of tlie comparative anatomical and of the embrj'ological 

 methods in the determination of phylogeny. 



The materials that the phylogenist has before him are, first, the 

 animals themselves; and second, the accumulation of previous 

 studies upon their morphology. If the latter were always accurate 

 repi'esentations, they Avould give one, in a short space of time and 

 with a minimum of labor, the facts he needs ; but very few of the 

 large array of morphological monographs are even tolerably accu- 

 rate, and because of this one frequently goes astray in trusting to 

 the descriptions of others. Hence, first and foremost, our ideas of 

 morphological details must be accurate — i. e., without preconceived 

 bias of interpretation — and, as far as possible, we should ourselves 

 study the organisms which we compare. In the next place the 

 whole method must be synthetic, comparing object with object 

 until gradually a connected mental superstructure is formed, all the 

 jmrls of which have been separately studied. This by no means 

 implies the avoidance of working theories, for it has been the expe- 

 rience of the naturalist that such theories are exceedingly fruitful 

 in directing research; but it does imply that the Avorkiug theory 

 should be considered as such and as nothing more, until it can 

 be demonstrated that there are no overlooked facts Avhich may 

 be in contradiction to it. At every point the method should be 

 tested as well as the observation. By adding comparison to com- 

 parison, provided we are working with a method in whose relative 

 correctness we can feel confidence, we may expect fuller unanimity 

 of result and gradual lessening of confusion in interpretation. 



I. The Possible Modes of Classification. 



A classification is necessary to enable a concise grouping of the 

 facts ; a phylogeuetic classification should be the statement of the 

 origin and transformation of organisms. Obviously there is a 

 necessity of considering whether the study of structure alone is 

 sufiicient for determining this racial progress, or whether the other 

 attributes of organisms should be considered. In a word, why 

 should the strictly morphological classification, the one dominant 

 in present thought, be granted precedence ? 



Any of the following classifications might be instituted, liesides 

 the morphological : ( 1 } Physiological, one based upon the degree. 



