650 



SCIENCE 



[N. S. Vol. II. No. 46. 



the power of reversion to the original spe- 

 cies, if only each individual is allowed 

 to choose its mate as in a natural 

 state. Consider the constancy and, on the 

 other hand, the wonderful plasticitj^ of the 

 organization of this familiar but remarkable 

 bird. Contemplate the wonderful power of 

 change from, and the more wonderful 

 power of reversion to, the original type 

 transmitted through generation after gen- 

 eration and retained through centuries, the 

 only medium being a speck of matter so 

 minute that it would not be indicated by a 

 very delicate balance, and tell me whether 

 you think it probable that the powers re- 

 ferred to are due to the original material 

 properties of the fragment of matter con- 

 cerned, or whether this acts only as a car- 

 rier of the marvelous power belonging to 

 tlie living world only and originating in the 

 infinite. Never before the present time 

 was there any possibility of approaching 

 the thorough investigation of the important 

 question of life. Our much wider range of 

 knowledge concerning the structure and 

 action of many living organisms widely 

 separated from one another has, in fact, 

 enabled us to consider the question from 

 many new points of view ; and, although 

 the issue between contending parties is per- 

 haps more pronounced than ever, the prob- 

 abilitj^ of arriving at the truth has immeas- 

 urabljf increased, if, indeed, it has not al- 

 ready reached something approaching cer- 

 tainty. It is curious that, although knowl- 

 edge of minute structui-e and of the actual 

 phenomena characteristic of living matter 

 has been widely spread, the important ques- 

 tion of the nature of life and its resemblance 

 to and differences from all physical and 

 chemical actions known has only been very 

 imperfectly debated. One would think that 

 the inquiry laj' far away from the paths 

 familiar to most educated persons, but the 

 most important points bearing upon the in- 

 quirj^ can now be made intelligible to edu- 



cated minds without much difiBculty, so 

 that many thoughtful persons may be able 

 to form a judgment of their own, at least 

 concerning the direction in which the truth 

 will probably be discovered. 



Among the broad and well-known facts, 

 then, not to be explained by the physical 

 view of vital actions is the vast subject of 

 heredity so remarkable in every department 

 of nature, both for the long periods of time 

 of its continuous operation and for the mag- 

 nitude and enormous importance of the re- 

 sults when considered in connection with the 

 verj' minute quantity of matter concerned. 

 Is the transmission of characteristics of mi- 

 nute structural details of extraordinary con- 

 stancy handed down from generation to gen- 

 eration for hundreds or thousands of years 

 by the very minute particle of matter which 

 we know to be concerned in the process to 

 be attributed to the physical properties and 

 chemical composition of the matter involved 

 or to vital power communicated to this 

 from the immediate predecessor ? 



We have now followed the phenomena 

 common and peculiar to all living to the 

 seat of their activity in living matter. In 

 centers far more central than our present 

 means of investigation will permit us to 

 penetrate living particles communicate, and 

 without loss, their marvellous powers to 

 some of the recently selected molecules of 

 the non-living pabulum. It would seem 

 that now for a time the ordinary properties 

 of matter are held in suspense or are over- 

 come. Here occur analytical operations of 

 the most stupendous kind, which are car- 

 ried out verj' quicklj' and in the quietest 

 manner, without apparatus or reagents, and 

 without resort to a high temperature. The 

 matter which is the seat of these phenomena 

 is as clear as water, structureless, and com- 

 posed of very few elements which, if the mat- 

 ter dies, easily take the form of an albumin- 

 ous substance with fatty matter and salts. 

 Duringtheliving state theatoms of the mat- 



