26 



NA TURE 



[May 14, 1874 



from the south, and there is no difference in the character or 

 appearance of the moraines left on both sides of the equator. 

 Second, because, excepting on the supposition that the ice 

 extended, at least along some meridians, both from the south and 

 the north nearly to the equator, at the same time, we cannot 

 explain the distribution of those animals and plants that are 

 found in the temperate zones of both hemispheres, separated by the 

 whole width of the tropics, over which they cannot now pass. 

 For example, there are more than forty flowering plants of North 

 Ameiica and Europe which are also found in Terra del Fuego. 

 Darwin's theory that these plants were driven to the high lands 

 of the tropics during the glacial period, and followed the retreat- 

 ing ice in its retrocession, must fall to the ground if the ice did 

 not exist in both hemispheres at the same time. (See " Origin 

 of Species," p. 405, &c.) 



10. The piimg-up of water around the poles in the form of ice 

 could not fail to aftect the level of the ocean. Mr. Alfred Tylor 

 has calculated that the accumulation of the ice in the northern 

 hemisphere alone would alistract so much water as to lower the 

 level of the sea 600 feet ; and if, as I believe, the glacial period 

 occurred at the same time in both hemispheres, the level of the 

 ocean must have been lowered at least 1,000 feet. 



II The theory of the lowering of the level of the sea during 

 the glacial period is directly opposed to the generally accepted 

 one of a great submergence of part of England and Scotland to a 

 depth of about 2,000 feel, when the marine shells of Moel Try- 

 faen and Macclesfield were deposited. The facts on which this 

 theory of submergence is based can be otherwise explained. The 

 shells are broken or worn, and generally mixed amongst other 

 transparent materials. They are just where they ought to be 

 found on the supposition that an immense body of ice coming 

 down from northern Ireland, from Scotland, and from Cumber- 

 land and Westmoreland, filled the basin of the Irish sea, scoojjed 

 out the sand with the shells that had lived and died there, and 

 thrust them far up amongst the Welsh hills that opposed its course 

 southward and around the great bight of which Liverpool forms 

 the apex. Excepting some raised beaches around our coast, 

 which were probably formed after the glacial period, and in no 

 case reach more than 100 feet above the present level, I believe 

 there is no evidence of the submergence of Great Britain either 

 during or since the glacial period. THOMAS BELT 



Lakes Vv^ith two Outfalls 



The subject of double outfalls is of some interest, if only as 

 showing (he necessity of accurate observation, and the difficulty 

 of ascertaining the truth in matters apparently of siinple fact. 

 In Nature, vol. ix. p. 485, Mr. W. B. Tlielwall brings 

 forward two instances of lakes with double outfalls, and states 

 that he has passed two or three more. Now, as regards that 

 upon the Fille Fjeld, which he describes from personal observa- 

 tion, I beg entirely to call in question his accuracy. I passed 

 the locality during each of the two last summers, and my attention 

 was drawn to the position and nature of the watershed, es- 

 pecially during my visit of last summer, when I had carefully 

 inquired into the asserted existence of a natural double outfall at 

 the Lesjeskaagen Vand. (See Nature, vol. viii. p. 304 ; also 

 Colonel Greenwood's and Mr. R. B. Hay ward's letters, Nature, 

 vol. viii. p. 382.) 



Mr. W. B. Thelwall says : — " Between Nystuen and Skogstad 

 is a chain of lakes crossing the watershed, the highest of which 

 (not the one marked on the ^'ei-cart over Norge, I think), sends 

 its waters to the west, past Nystuen to the Sogne Fjord, at 

 La;rdals6ren, and on the east by the Lille Mjosen, and Aadalen 

 to the Tyrifjord, and so past Drammen to the Christiania Fjord. 

 This lake is a small one, and the double outflow is close to the 

 high road." 



Now this statement is inaccurate in all the essential details. 

 The division of the waters is aoi between Nystuen and Skog- 

 stad, but on the other side of Nystuen between it and Maristuen. 

 The water wliich passes Nystuen does tiot flow towards the west 

 to the Sogne Fjord, but to the east towards the Lille Mjosen, ai 

 I carefully ascertained when I was staying at Nystuen. This is 

 rendered certain, too, by the fact that the land rises to the west 

 of Nystuen, the actual division of the waters being about 100 or 

 105 feet, by myaneioid barometer, above Nystuen. Moreover, 

 having scrambled up a steep mountain close behind Nystuen, 

 whence the view on a clear day is of the wildest character, I had 

 a bird's-eye view of the whole district in debate, and examined 

 it carefully with a good field-glass, with a view to detecting any 



Evidence of a double outflow. I came to the conclusion that the 

 division of the waters took place in the boggy bottom of the 

 valley to the west of Nystuen, and that it would be impos- 

 sible to say exactly where it was. To the westward of this 

 boggy place is indeed another lake, of which the waters flow to 

 the Sogne Fjord ; but this like is several miles to the west of 

 Nystuen, and separated from it by dry land, rising 100 feet or 

 more above the levels of the water in the two lj.k-j-. 



Whether lakes with two outflows exist or not, it is difficult to 

 avoid feeling that Colonel Greenwood was warranted in his 

 former incredulity upon the subject. W. Stanley Jevons 



Trees Pierced by other Trees 



UNDEii this heading your correspondents discuss two distinct 

 questions as if they were thfe same, namely the piercing of the 

 stem of a tree by the head of another, as supposed by Mr. 

 Mur|ihy, and the growth of the roo/ of a plant in or on another 

 tree. Nothing can be more common than this last. Wherever 

 soil aggregates the roots of seeds will grow as a ma'ter of course. 

 More than this, trees will strike roots into soil collected in their 

 own forks, as I can show here, or down the rotten wood of their 

 own trunks. A remarkable case of this may be seen in a yew 

 tree in West Tisted churchyard near here. But nothing can be 

 more opposite than the growth of the root and that of the head. 

 The root grows to darkness; the head to the light. 



Alresford, May 1 1 George Greenwood 



[This correspondence must now end. — En.] 



The supposed Antipathy of Spiders to Chesnut Wood 



Some years back, while walking in the cloisters of New 

 College, I remember a resident Fellow (since deceased) telling 

 me that spiders were never known to occur in the woodwork of 

 the roof, and attributing their absence to the chesnut timber, of 

 which it was framed. 



It has been asserted that this wood, which was formerly sup- 

 posed to be that of the chesnut, really belongs to Qiwnus sessi- 

 lijlora, but I do not know if that is still held to be the case. 



The roof of Westminster Hall was at one time considered to 

 have been constructed of chesnut ; has any such story been 

 heard of in connection with it ? K. A. Pryor 



13 Bury Street, S.W. 



AN EXPERIMENTAL OBSERVATION ON 

 HAY FEVER* 



" 'T^HE accompanying brief but most interesting paper 

 ■*• was received a day or two ago. Believing that it 

 may bring relief to those who during the coming warm 

 weather may be attacked with hay fever, Prof. Tyndall 

 forwards it, with his compliments, to the editor of 

 Nature." 



From what I have observed (says Prof. Binz) of recent 

 English publications on the subject of hay fever, I am led to 

 suppose that English authorities are inaccurately ac- 

 quainted with the discovery of Prof. Helmholtz, as far 

 back as 186S, of the existence of uncommon low oVga- 

 nisms in the nasal secretions in this complaint, and of the 

 possibility of arresting their action by the local employ- 

 ment of quinine. I therefore purpose to republish the 

 letter in which he originally announced these facts to 

 myself, and to add some further observations on this 

 topic. The letter is as followsf : — 



" I have suffered, as well as I can remember, since the 

 year 1847, from the peculiar catarrh called by the English 

 ' hay fever,' the speciality of which consists in its attacking 

 its victims regularly in the hay season (myself between 

 May 20 and the end of June), that it ceases in the cooler 

 weather, but on the other hand quickly reaches a great 

 intensity if the patients expose themselves to heat and 

 sunshine. An extraordinarily violent sneezing then sets 



* Uy Prof. Binz, of Bonn, 



t Cf. Virchow's.^rc/HV', vol. .\lvi. p. 100. 



