November 15, 1895.] 



SCIENCE. 



647 



chanical action that produces the result'? 

 When and what is the machinerj' said to 

 be present, and how is any ' molecular 

 mechanism ' to be demonstrated in such 

 transparent substance? Aidhority alone 

 steps forward and insists upon laws and 

 properties and tendencies, declares to us 

 what we are to believe, and prophecies what 

 our successors will discern in the future. 



Before the year 1860, after having carried 

 on observations upon the tissues of plants 

 and animals in many departments of living 

 nature, and from the earliest period of 

 development to the fully formed state and 

 into old age, under the highest magnifying 

 powers (from 700 to more than 2000 diam- 

 eters) and with great advantages as regards 

 the preparation of specimens, I was led to 

 draw a distinction in each tissue, organ or 

 organism between the living growing forma- 

 tive matter and that which had been formed 

 and could not reproduce itself or give rise 

 to more formed matter. I was gradually 

 led to the general conclusion that every 

 form of the living, growing matter was ab- 

 solutely distinct from every kind of the re- 

 sulting formed matter produced by it, and, 

 further, that the influence upon the non- 

 living pabulum was peculiar and belonged 

 to all living matter, but to this onlj^, and 

 that it was not comparable with, or allied 

 to, any other known property, power or 

 action of matter. These conclusions were 

 illustrated in detail and were published in 

 1861. The preparations were shown to my 

 class of physiology in this College and dur- 

 ing lectures at the Eoyal College of Physi- 

 cians of London, and further discussed in 

 memoirs published in the Transactions of 

 the Eoyal Microscopical Society and in 

 several works published at that time and 

 since. It seemed to me that there were no 

 indications whatever of the faintest analogy 

 between the two kingdoms of nature — the 

 living and the non-living — no indications 

 of any gradation from matter in the non- 



living state to that of life, while all living 

 matter, from the very lowest to the very 

 highest, exhibited certain common char- 

 acters, being always colorless, structure- 

 less, capable of independent movement as a 

 whole or in part, caj)able of growth, with a 

 power of selecting certain substances and 

 rejecting others, having structural formative 

 power and powers of affecting chemical 

 change, rendering it certain that the origin 

 of matter so endowed was not direct from 

 the non-living, and that this doctrine sooner 

 or later would have to be abandoned. The 

 warmest advocates of the latter view have 

 never given adequate reasons for the faith 

 they pi'ofessed, or answered the many ob- 

 jections advanced against the conclusions 

 they accepted and taught. All the parti- 

 cles of living matter actively concerned in 

 the formation of tissues and organs, easily 

 seen under a power of 200 diameters, are 

 less, and most of them considerably less, 

 than the TjyVtJ part of an inch in diameter. 

 In the absence of such living particles noth- 

 ing can be formed or secreted. If we are 

 to form any accurate conception of the ac- 

 tual phenomena which occur when some of 

 the matter of these minute living particles 

 is resolved into tissue or secretion, it is 

 necessary to study the matter very atten- 

 tively with the aid of the highest powers, 

 and then we can expect only to learn some 

 of the broader changes which occur. The 

 actual conversion probably occurs in parti- 

 cles of matter far more minute than can be 

 discerned with the highest powers at our 

 disposal. Most important facts, however, 

 have been demonstrated with reference to 

 the movements of many of these bioplasts. 

 Where fibrous or other tissues are formed 

 which are to be laid down in parallel lines 

 the fibre is as it were spun off as the parti- 

 cle of living matter (bioplast) moves up- 

 wards or downwards along the tissue al- 

 readjr formed, and thus fibre after fibre is 

 added to those already existing. In some 



