1898] 143 



OOERESPONDEl^OE 



AVASPS 



I AM grateful to ]\lr A. 0. Walker for his letter {Natural Science, vol. xii., p. 72). 

 I see no difficulty in the wet of the winter of 1896-7 affecting the hibernating queens. 

 The wet period that I specified included the autumn months of 1896 and the early 

 spring mouths of 1897 — i.e. the months during which the queens are searching out 

 winter quarters and those in which they are endeavouring to find resting sites. In both 

 of these occupations they are fully exposed to atmospheric influences. I have previously 

 (Natural Science, vol. vi., p. 178) mentioned that I have seen a wasp on the wing 

 as early as February 7th, and I may now add that I saw several as late as Novemljer 

 13th, 1897. I am fully prepared to admit that while actually in hibernation the rain, 

 probably, has no direct efiect upon the queens. I have shown in the article last referred 

 to that cold does not kill hibernating wasps, and this opinion is held by many farmers 

 with whom I have conversed npoa insect pests in general. The year 1889, (quoted by 

 Mr Walker, does not appear to me in any way opposed to my theory, but rather to 

 support it. Mr Walker's summary shows that the temjierature and rainfall of March 

 1889 were not exceptional. April was '2'i)^¥. below average temperature, with a 

 rainfall 2 '61 inches above average. The low temperature would probably keep 

 the queens hibernating and prevent them starting the risky business of nest-formation ; 

 in other words, probably the queens were not on the wing nntil the rainy period was 

 ovei". The temperature of May was 1'7°F., and the rainfall 0'86 inch above average — not 

 a very serious amount. There is no doubt that a high temperature acts favourably on 

 wasp-colonies ; Janet has proved this beyond dispute, and it is equally possible that a 

 low summer temperature is unfavourable though it could hardly ever become actually 

 destructive. 



I can olfer no explanation of the exceptional occurrence in Mr Walker's house early 

 in September. It would be interesting to know if a nest was near the house, and also 

 if there was anything going on, such as fruit-preserving, which would strongly attract 

 the wasps indoors. I fancy that in any year wasps may be found fairly plentiful in the 

 Avindows of j^astry cooks' shops and similar sugar-laden spots. 



OsAVALD H. Latter. 



Charterhouse, Godalming. 



REPRODUCTIVE DIVERGENCE 



In the last month's number oi Natural Science, Dr Karl Jordan adversely criticises the 

 further demonstration I gave of a theory which I had suggested in a former number of 

 the Journal (vol. xi., p. 181). I do not propose, however, to again encroach on your 

 space at any length as I have been assured by several zoologists of standing that on the 

 one hand my demonstrations of the correctness of the theory appeared to them quite 

 sound and convincing, whilst on the other hand they were unable to comprehend the 

 objections raised by Dr Jordan. The arithmetical part of the jiroof has also been 

 worked through again liy myself and independently by a friend, and found correct. I 

 therefore think that the question of the validity or otherwise of my arguments, and of 

 those brought forward l;iy Dr Jordan, may be safely left to the judgment of those readers 

 of Natural Science who are sufficiently interested in the subject to read through care- 

 fully what has been written on both sides. 



I wish to take the present opportunity of saying that if any mathematician should 

 think it worth his while to attack the problem, I should be exceedingly obliged by his 

 so doing. Thus it seems to me possilile that, given the amount of variation originally 

 present, and also the degree of infertility between the various individuals, one might be 

 able to express by means of a general formula the amount of divergence taking place 

 after a given number of generations. H. M. Vernox. 



The Zoological Station, Naples. 



THE DOCTRINE OF UNIFORMITY 



Although I quite agree in the main with Sir H. Howorth's strictures in the January 

 number anent "the great fetish of the modern geologist, the doctrine of Uniformity," 

 nevertheless I fail to sec what scholasticism and metaphysics have got to do with the 

 matter. Nor would I pronounce anathema on " the scholastic and ridiculous d priori 

 prejudices of superior men," provided that they were the oH'spring of true scientific 

 ideas and intelligence. That, indeed, is the most important point. In the country of 



