LIXXEAX SOCIETY OP LOXUOX. 97 



will reproduce themselves absolutely pure if steps ai-e taken to 

 prevent hybridization. According to the author of the paper 

 (Dr. Lotsy), we should have to consider that all these various 

 and distinct forms have suddenly originated by the crossing of 

 two individual plants of Beta maritima, rather than by loDg con- 

 tinued selection, as has generally been supposed. Beyond all 

 doubt, selection has played a very important part in bringing 

 tliese several forms to their present state of perfection. 



I imagine we all felt that the paper afforded much valued light 

 upon a very obscure problem, but that the Author's theory and 

 claims by no means met all the difliculties of the case. 



]\Iiss E. E. Saux'deks stated that with much of what Dr. Lotsy 

 had said one felt to be in agreement, but that when he pushed 

 lu's theory to its extreme limit, when cross-fertilization was put 

 forward as the sole cause of evolution, one felt unable to agree 

 with him. 



Certain cases had already been mentioned by previous 

 speakers in which it was dirticult to accept Dr. Lotsy's view. 

 Many others might be brought forward, as, e. g., the case of 

 certain monstrosities which breed true, or the case of doubling in 

 such a form as the stock. That the form of DiijitaJis jnirjmrea, 

 which is found to turn up from time to time, in which stamens 

 take the place of petals, should be due to crossing, seems much 

 less likely than that it should be due to some irregularity at some 

 point in the process of cell-division, and the same with the Stock. 



One cannot help feeling tliat Dr. Lotsy's theory does not take 

 us back to the beginning, that it does not give us the opening 

 chapter in the story of Evolution, and that it requires, to use his 

 own simile, that the packs of cards should all have been incomplete 

 to start with. 



Tlie Peesidext said that, at this late hour, he would only con- 

 tribute a few words to the discussion. 



The ditierent species of animals do not freely interbreed, as 

 many plants appear to do. However difficult it may be for the 

 human zoologist to determine what is a species, the problem 

 appears to present no difficulty whatever to animals themselves. 

 It is exceedingly rare for these fundamental instinc-ts to go astray, 

 and, when they do, it is exceedingly rare for fertile offspring to 

 be produced. Animals do not act upon the lax principles which, 

 as botanists tell us, are freely followed by plants. 



He also desired to associate himself with the arguments brought 

 forward by other zoologists. A small portion of a species was 

 often cut off from interbreeding with the rest by isolation on an 

 Oceanic Island. According to Dr. Lotsy's hypothesis, the varia- 

 tion of such isolated sections should be checked — as a matter of 

 fact, it was kno^^■n in many conspicuous examples to be increased. 



LIXX. SOC. PEOCEEDIXGS. — SESSION 1913-191-i. 7l 



