PKKSihKvrs Ar>r>HEss — 8kct. L>. 145 



We are mutv used now to startling results in recent scientific 

 researches, wliich (lestro\- our most fundamental conceptions. I need 

 only remind you of tlie unexpected results which the discovery of 

 radium has brought forward, and of tiie results of recent researches in 

 animal and vegetable physiology, to some of wliich I will refer later 

 on. An old teacher of mine, Professor Landolt, a man with a 

 thoioughly sound reputation, stated quite recently, that in certain 

 ciiemical reactions, which he had carefull}^ investigated, there w^as 

 undoubtedly a loss of substance, which was greater than the possible 

 experimental error, a small portion being evidently dissociated into 

 some elementarj' substance, of which we have ver^^^ little, if any, con- 

 ception. If our species also evaporate, when they are carefully 

 examined, then the vast amount of labour and monej^ spent on tiieir 

 elucidation would naturally be thrown aw^a3% and it seems, therefore, 

 legitimate to inquire whether they are so shadowy as some people 

 would make us believe. 



Nobody can realise more plainly' than I do, how difficult it is to 

 adjust specimens to catalogues and descriptions, and I would be the 

 last to attempt to defend the Linnrean concept of the species as an 

 entity immutable and constant, incapable of either degeneration or 

 modification; but I am afraid that the fact that species vary to a 

 greater or lesser extent has in a certain measure obscured the question 

 whether species are entities at all, because it has prevented us from 

 defining accurately what a species is. Such a definition is even to- 

 day practicall}- impossible, yet if they were such elusive phantoms as 

 some think, we might well leave them altogether and follow the 

 monographer of the corals in the British Museum, by calling new 

 finds, as a writer recentl}' put it, " Chunk No. 1 from the Australian 

 Reef " or " Chunk No. 2 from the Indian Ocean." However, it can- 

 not be too strongly insisted upon that classifying little bits of the hard 

 parts of corals does not mean dealing with species. 



Only recently a distinguished mycologist has stated : " The reality 

 of the species is neither evident nor demonstrated ; it is a postulate 

 which is at tlie bottom of all sj^stematic studies. The limits of real 

 species are for the most part unknown to us ; w^e give them conven- 

 tional limits determined solely by our means of investigation and 

 according to the wants to which classification responds." But I 

 venture to think that he is to a certain extent begging the question. 

 Mycologists especially are confronted with such difficulties in deter- 

 mining the range of a species, that they are driven to the necessitj'' 

 of giving specific names as it were to fragments of species, just as- 

 paheontologists will give a specific name to an isolated tooth, another 

 name to isolated leg-bones, &c., until a lucky chance enables them to- 

 sweep away numerous names and combine them under the name of the 

 whole animal. Similar exaniples will occur to everybody fannliar 

 with vegetable pah^^ontology. 



K 



