189S] NOTES AND COMMENTS 221 



subject would be" — not only for Sir William Crookes — "an act of 

 cowardice." 



Stereochemistry and Vitalism 



In connection with the above remarks, it is interesting to note that 

 the Presidents of the Sections for Mathematical and Physical 

 Science and Chemistry — Professors Ayrton and Japp — dealt with 

 subjects which might equally well have been considered in the 

 Biological Sections, while the President of the Zoological Section 

 applied to certain biological problems the methods of mathematics. 

 Professor Ayrton described certain interesting experiments on the 

 smells of substances. Professor Japp considered certain facts of 

 stereochemistry in their relation to the fundamental problem of life. 

 He pointed out that all inorganic compounds were symmetric, and 

 that the forces producing them were either symmetric, or, if asym- 

 metric, then asymmetric in two opposite senses. Compounds of 

 one-sided asymmetry originate with the living world, and are only 

 known to be produced by some selection in which living organisms 

 must directly or indirectly take part. It is of course possible that 

 some day the isolation of asymmetric compounds may be proved 

 possible without the intervention of even the directing intelligence 

 of the chemist in his laboratory. Professor Armstrong, who spoke 

 after the address, evidently thought that this would be proved before 

 the next meeting of the British Association in Bristol. We are as yet 

 only on the threshold of the problem, and fresh methods of investi- 

 gation or fresh conceptions may upset the prophecies of to-day. 

 For the present, however, Professor Japp has done good service in 

 setting before us one of the difficulties to be overcome before the 

 vitalistic hypothesis can be rejected. 



The Need of Numerical Investigation in Biology 



Professor Weldon, choosing a subject which the ordinary naturalist 

 is apt to consider abstruse and uninviting, succeeded in delivering 

 an address that both for content and exposition was one of the 

 successes of the meeting. Entitled, " Some objections to the theory 

 of Natural Selection," it was in the main an attempt to expound to 

 biologists the modern doctrine of chance, and to show that the 

 variations which actually occur in the animal world are neither 

 more nor less definite than those which result in the tossing of 

 ha'pence or the casting of dice ; further, that these ' chance varia- 

 tions ' do afford scope for the action of Natural Selection in a way 

 that admits of accurate measurement. The instance taken was the 

 variation in frontal breadth of Carcinus maenas from a particular 

 patch of beach in Plymouth between 1893 and 1898. It was 

 shown that the frontal breadth was diminishing at a rapid rate in 

 this particular race, and evidence w r as adduced to prove that this 



