REVIEW OF THE POSITION 17 



sufficient. Accordingly he has invented from immemorial times 

 his oil lamps., rushlights, tallow and wax candles, gas and electric 

 light for the illumination of Ins streets and houses. Prehistoric 

 man did not seem to need them, as he thought. These useful 

 examples of applied knowledge were obviously brought into use 

 for showing man better where he was going and where to go, what 

 he was doing and what he wished to see. I hope this trite remark 

 may be pardoned, for there is another form of light which suits my 

 purpose of illustrating the aspect of Weismannism referred to above, 

 that is the light of a lighthouse. The ancients in their crude way 

 saw the need for this and as far back as the days of Ptolemy II. a 

 tower to give light was erected on the island of Pharus, off the 

 Egyptian coast, and it was called a pharos. Man found it necessary, 

 as navigation and seafaring advanced, to use this principle more 

 and more, and on headland, sandbank and rugged coast has built 

 noble structures to aid the sailor in his dangerous course. The 

 oldest and finest of these in Great Britain is the Eddystone light- 

 house, built first in 1695 by Winstanley and finally by Smeaton 

 in 1756-9. For what reason is a lighthouse built and placed where 

 it is ? For the precisely opposite reason to that of the domestic 

 candle. While this shows you where to go and how better to do 

 your immediate business, a lighthouse is for the main purpose of 

 showing a mariner where he should not go. It has no relation to 

 adornment or pleasure. It does not invite you to come in your 

 vessel and admire it. It tells you to go away and avoid the sunken 

 rock or treacherous sands. 



I submit here the suggestion with all deference, that the final 

 work of Weismann has lighthouse value of a high order, as to the 

 modus operandi of evolution. His greatness as a biologist, his 

 candour and skill in dialectics, have built up a veritable lighthouse 

 which may usefully warn the seeker after the path of evolution that 

 he must turn elsewhere if he would not founder upon a reef of facts. 



The two great contributions to evolutionary thought that 

 Weismann has made should be considered separately, the theory 

 of germ-plasm and that of evolution, though the latter seems to 

 be the necessary outcome of the former. But the truth of Weis- 

 mann's view of heredity does not of necessity require the error of 

 his theory of evolution. 



Romanes on Weismann. 



For this study the examination of Weismannism by Romanes 

 published in 1893 is of great value. I need only refer here to the 

 mam conclusions of that lucid and learned examination. 



