4 o 



NATURE 



[July 8, 1922 



article were offered in the hope that they would 

 assist in settling the difficulties that had arisen 

 between members of the staff and the council. — 

 Editor, Nature.] 



Ball Lightning. 



Amongst the notes in Nature of August 4, 1921 

 (vol. 107, p. 722), is a reference to the occurrence 

 of ball lightning during a thunderstorm at St. John's 

 Wood on June 26. The phenomenon, it is added, is 

 of great rarity. The following therefore, apparently 

 another instance of this phenomenon, may be worthy 

 of record in Nature. It was communicated at the 

 time to the Meteorological Office in Sydney. On 

 the evening of January 13, 1920, a very severe 

 thunderstorm with heavy rain occurred in Sydney. 

 About 9 P.M. I went out on to the verandah of my 

 house at Neutral Bay, which overlooked the harbour, 

 to watch the progress of the storm. This was soon 

 after its beginning, and the lightning was very vivid 

 and frequent and the rain heavy. Looking towards 

 Mosman Bay, I saw descending, rather slowly in an 

 oscillating way, a large ball of light, seemingly about 

 the size of a Chinese lantern. This took about 

 two seconds to descend and be lost to sight in the 

 hollow towards which Mosman Bay itself lay. The 

 light seemed to have a violet tinge. No rays emanated 

 from it. No noise was heard. 



J. B. Cleland. 



The University, Adelaide, South Australia 

 May 8. 



Ouramoeba 



I shall be glad to know whether any readers of 

 Nature interested in the Rhizopoda have met with 

 specimens of Leidy's Ouramoeba botulicauda ? 'While 

 examining some squeezings of Sphagnum from Wood- 

 bury Common, near Exeter, a few days ago, I found 

 an active individual and had it under observation for 

 some time. Fig. 14 on PI. IX of Leidy's " Fresh- 

 water Rhizopods of North America " might have been 

 drawn from my specimen. 



It is now generally conceded that the characteristic 

 jointed appendages are filaments of a parasitic alga, 

 and Archer described amoebae in this condition, from 

 Ireland, in 1866, but I am anxious to ascertain whether 

 similar observations have since been marie in other 

 parts of Great Britain ? F. R. Rowley. 



Royal Albert Memorial Museum, Exeter, June 8. 



Dr. W. L. Poteat of Wake Forest College, N.C. 

 (U.S.A.), published in Nature of May 24, 1894 

 (vol. 50, p. 79), a letter recording his finding of 

 Ouramoeba in Wake Forest, N.C, and asking for 

 citations of other records. To this inquiry Mr. 

 Rowley's note furnishes a late reply, for there has 

 been no other (in Nature) in the interval. There 

 is now, however, a good deal of literature on the 

 subject. Ouramoeba, as Dr. Poteat was the first to 

 demonstrate beyond doubt, is simply Amoeba spp. 

 (A. nobilis Penard, proteus Rosel, binucleata Gruber, 

 villosa Wallich) infested with fungal spores and fi la- 

 ments. In 1898, Mr. Martin F. Woodward of the 

 Royal College of Science sent Dr. Poteat drawings 

 of an infested Amoeba presumably found in the 

 neighbourhood of London (Science, N.S. viii., 1898, 

 p. 781). There does not appear to be any other 

 record for England. The latest memoir by E. W. 

 Gudger, "On Leidy's Ouramoeba," is in Journ. 

 Elisha Mitchell Sci. Soc, xxxii., 1916, p. 24. 



R KlRKPATRICK. 



British Museum (Natural History), London, S.W.7. 



NO. 2749, VOL. I 10] 



The Elliptic Logarithmic Spiral. 



With reference to Dr. Rowell's letter in Nature 

 of June 3, p. 716, it may be pointed out that his 

 curve, so far from being new, is briefly discussed 

 in Besant's " Dynamics " (Besant and Ramsey, 

 " Treatise on Dynamics," pp. 101-2). The equa- 

 tions of the curve may be written 



x =af 4-077 1 



y =7! +8yJ 

 where (f, 1;) lies on a certain logarithmic spiral. 

 The curve is thus obtainable from this spiral by a 

 homogeneous strain, whence, amongst others, it will 

 have the property that its various branches cut a 

 radius vector at the same angle : this angle differing 

 for different radii vectores. C. E. Wright. 



Artillery College, Woolwich, June 19. 



Seasonal Incidence of the Births of 

 Eminent People. 



In order to find, if possible, the causes which under- 

 lie the production of increased numbers of eminent 

 intellects at certain periods (as, for example, the year 

 1809 and a year or two before and after it), I collected 

 statistics of the dates of birth of more than two 

 hundred eminent persons. The list consists chiefly 

 of creative intellects, — poets, literati, musicians, 

 painters, architects, men of science, explorers, and in- 

 ventors, with a few statesmen and military men. 

 Analysis of the dates shows that the greater number 

 of these persons were born in the colder months of 

 the year ; but the distribution of the numbers is 

 somewhat erratic. February is distinctly the richest 

 month, having produced a galaxy of eminent persons ; 

 December comes next ; August and June are the 

 richest among the warm months. 



Sixty pre-eminent names, chosen for no reason but 

 their pre-eminence, were found to be distributed as 

 follows : — In warmer months : April, 4 ; May, 6 ; 

 June, 7 ; July, 2 ; August, 5 ; September, 3 ; total, 

 27. Iii colder months : October, 4 ; November, 1 ; 

 December, 9 ; January, 5 ; February, 9 ; March, 5 ; 

 total, 33. 



The difference is more evident when the months 

 are taken in groups of three, as follows : December to 

 February, 23 ; March to May, 15 ; June to August, 

 14 ; September to November, 8. 



In order to find whether this distribution corre- 

 sponds with the ordinary distribution of births through 

 the twelve months, I compared the numbers with the 

 average of twelve years taken at a venture from the 

 Registrar General's Quarterly Returns, namely, the 

 period 1844-55. The figures are too numerous for 

 quotation, but it may suffice to say that I could find 

 no correspondence between the ordinary distribution 

 of births and the distribution of births of eminent 

 persons. In the Registrar General's Returns the 

 order of average frequency for the quarter-years 

 was as follows : April to June, July to September, 

 January to March, October to December. 



Climate can scarcely explain the distribution, 

 (See letter from Dr. Robert W. Lawson, Nature. 

 June 3, p. 716.) Cold weather is not unhealthy for 

 children, and in fact the diseases of the hot months are 

 among the most fatal for them. I suggest that the 

 reproductive organs, especially the germ cells, are more 

 vigorous at certain seasons, producing offspring of 

 higher quality. The many eminent persons born in 

 the winter months, December to February, were con- 

 ceived in the spring, the time of increased vigour of 

 most living things ; whereas the few born in the 

 autumn months, September to November, were 

 conceived in the winter. F. J. Allen. 



Cambridge, June 17, 1922. 



