Dec. 31, 1874] 



NA TURE 



167 



olijcct-glasfcs would probably give matchless solar phoSograms. 

 Tlie 120 feet has 6 inches aperture, and would give a solar pic- 

 ture 13 '4 inches diameter. R. 



The Potato Disease 



I AM afraid I cannot regard the letter of your anonymous cor- 

 respondent "Inquirer " as written in altogether good faith. He 

 first misrepresents what I stated in ray letter of Nov. 20, which 

 he professes to quote, and tVien proceeds to ask me a question 

 which, if he had even glanced at my letter, he would have seen 

 was already answered. 



If I beg your indulgence for some further remarks suggested 

 by "Inquirer's " letter, I hope that they will be the last it will be 

 necessary to make. 



The number of Nature for Nov. 19 gave what pur- 

 ported to be an account of the " Report of the Potato Disease 

 Committee of the Royal Asjricultural Society." It contained 

 the following passage: — "Prof, de Eary has worked out the 

 scientific questions that occur as to the origin of the disease. It 

 is owing to a fungus [rcroiiospora iiifestaiis), which attacks the 

 leaves first, and after absorbing the nutriment of them, utilises 

 the petiole, and thus reaches ihe tubes " [sic). It appeared to me, 

 as it did to others, that the only me.ining which could be attri- 

 buted to this was that we owed to Prof, de Bary all the know- 

 ledge we at present possess with regard to ihe disease. 



I therefore thought it fair to point out in the following number 

 "that all this snd a good deal more was a-certai.ied by the Rev. 

 M. J. Berkeley in this country, and by iMontagne in France, and 

 published by the former in a paper contribulei to the first volume 

 of the Journal of the Horticultural .Society in 1S46." It is almost 

 incredible that anyone with my letter Ijefore him should say 

 that I had asserted " the disi-o-'cry by the Rev. JNI. J. Berkeley 

 of the fact that the potato disease was due to the attacks of a 

 parasitic fungus," and should proceed to ask me for "a more 

 exact refireiicc to the records." 



Tile potato disease appeared on the Continent a few years 

 belore it worked such ravages in the British Isles. The moull 

 had been detected upon the foliage in France and BeLi.'.m, 

 but opinion was divided as to the pa;t it really pl.iyed. 

 And we have Mr. Berkeley's authority for asserting that even 

 iMontagne, to whom "Inquirer" attributes the discover'/ that 

 the pota'o disease was due to the attacks of a parasitic fungus, 

 did ;/(?/ support the "fungal theory." 



In this country Mr. Berkeley maintained it almost' single- 

 haiiiled against men of such weight as l.indley and Playfair. 

 His paper, which appeared in the Horticultural Society's Journal 

 in November 1845 (the whole volume is dated 1S46), really, how- 

 ever, settled the matter. 



It is perfectly easy to trace what Mr. Berkeley did by referring 

 to the horticultural papers of the time. Thus, he wrote to the 

 Gaii/enci's Chronicle, August 30, 1S45 (p. 593) : " The malady 

 by which potatoes are so generally affected this year, both in 

 this country and on the Continent, does not appear to prevail in 

 this neighbourhood. ... I have this morning received from 

 Dr. Montagn;, of Paris, some leaves affected with the mildew. 

 . . , The parasite of the potato does not appear to have been 

 observed before by systematists." On Sept. 6 (p. 60S) : "You 

 will be interested to learn that the mould upon the potatoes 

 which you sent me is identical with that upon the leaves, and 

 the same with what I have received from Paris. It appears, then, 

 that t/ie decay 0/ the liihers is proJiieed liy the same cause which 

 affects the hax'cs, viz., by the growth of a mould whose develop- 

 ment has been promoted by excessive wet." On Sept. 20 

 {p. 640) : *• In every case I find the Botrytis infesfans [now called 

 J'eroiiospora infestam] preceding the work of destruciion." 



All this is given with very full details by Mr. Berkeley in his 

 later paper. What I wish, however, particularly to point out is 

 that the admirable observation (contained in the words I have 

 itilicised) of the id.'ntiiy of the lungus which attacks the foliage 

 with that which destroys the potatoes was made absolutely inde- 

 pendently by Mr. Eerktley. Morren appears to have made it 

 about the same time. It is a sufficient proof of the estiuratiun 

 in which his investigations were held at the time, that Mon- 

 t.agiie relicquished the intention of writing upon the subject, 

 and transmitted his materials to Mr. Berkeley, by whom the use 

 of them is duly acknowledged. W. T. Thiselton Dyer 



Mr. Cuttell and Section Cutting 

 In your number of Nature just issued you have given an ex- 

 tract from the annual address of the President of the Roysl 



Society, in wliich reference is made to my labour of section eut- 

 tirrg. It is perfectly true that I have prepared more than a thou- 

 sand sections of coal plants, but it would be unfair to a very 

 efficient auxiliary not to mention the help he has afforded me in 

 this work. I require many sections of a much larger size than 

 my machinery is capable of cutting, and these have been pre- 

 pared for me by the skilled hands of Mr. Cuttell, of New 

 Cnmpton Street, London. 



In each of two instances, also, I am indebted to the same ex- 

 perienced lapidary for obtaining three sections out of small but 

 precious fragrnents, not more than from thr-ee-sixteenths to a 

 quarter of an inch in thickness. I am anxious to recognise these 

 services, and not to monopolise Mr. Cuttell's share of the credit 

 for the labours to which Dr. Hooker's report refers so kindly. 

 \V. C. WiLt.IAMSO.V 



Fallowfield, Manchester, Dec. 24 



Snakes and Frogs 



In' reading the letter of your correspondent, Mr. iMott, on the 

 cry of the frog, it struck nie as cut ious that there should be resem- 

 blances which people in countries wide apart should pitch on 

 the same phrase to indicate. Now, there could not be a better 

 way of conveying a sound which frequently greets one's ears in 

 the country in Bengal during the rains, than that which your 

 correspondent makes use of, "the cry of a new-born infant." 

 Few residen's in the country here, we take it, who have lived 

 any.vhere ntar jungle, will have failed to hear, and that tolerab'y 

 frequent, the unspeakably plaintive wail which indicates that the 

 remorseless ophidian has seized his prey, and that deglutition 

 has commenced. If one be tolerably quick he may, as 1 have 

 frcq'iently done, guide hiin=elf to the very spot by the sound of 

 the frog, and the snake will then, in his alarm and anxiety to 

 escape, frequently let the frog go, though he as often slides off 

 with it protruding from his n^^uth. We have the batrachians 

 in great force here, and of all tizes and noises, from the great 

 swaiip frog which, as soon as the lands are drenched in the 

 heavy rainstorms of May, commences its nocturnal bellowing, 

 down to the bronze tree frog with gilt eyebrows that keens uo 

 its meiallic 'ink. *^ ' 



The frog is connected with some of the religious ceremonies of 

 the ctuiitry ; and one may see here, as well as in Assam, the 

 curious custom of "bathing the frogs " in a cage. This is done 

 in time of drought to pi-opiiiate the rain god. Grahr is some- 

 times put out on a mat to sun, and to prevent the crows from 

 makii.g away with it, a frog is tied by the leg to a st.ake ; his 

 con^liiit hopping abi^ut acts as a deterrent to the crow. Hence 

 the native proverb denoting vicarious and unmerited suffering, 

 " The crow s!eils the gra n, and the string is round the 1 g of 

 the fiog." c. B. 



Budderpore, Eastern Bengal 



THE ANDERSON SCf/OOL OF NATURAL 

 HISTORV 



1\ T GST of our readers, »o doubt, have heard of the 

 ^^^ School of Natural History established by the late 

 Prof. Agassiz, in conjunction with some of his American 

 friends, shortly before his lamented decease. The first 

 report of the trustees of this institution, which has lately 

 been received in this country, gives a fuller account of 

 its foundation and subsequent progress than has yet 

 reached us. 



The plan of the school was first put forward by its 

 originator in a circular issued in Decetnber 1872, from the 

 Museum of Comparative Zoology at Cambridge, U.S.A. 

 It was proposed that courses of instructive lectures in 

 various branches of natural history should be delivered 

 by the sea-side, at Nantucket— an American bathing- 

 place— during the summer months, by Agassiz himself, 

 and by other naturalists belonging either to the same 

 insiituiion, or to other scientific establishments in the 

 United States, who had combined together to assist him. 

 The object of these courses was chiefly for the benefit of 

 teachers proposing to introduce the study of natural 

 history into tiieir schools, and for such students as were 

 preparing to become teachers. Besides the lectures it 



