2eo 



NA TURE 



[January 6, 1910 



aspect may exhibit a greater abundance of species, though 

 less well developed, from the continuous play of spores — 

 and rain — upon the trunk. 



Of north and south positions the same may be said, 

 i.e. the south is sheltered from fierce, cold north winds, 

 yet open to warm, rain-depositing winds. Again, once 

 established, cryptogams flourish on the southern aspect 

 best owing to its sunny character. North winds blow 

 when spores are not so abundant, and the same applies to 

 boisterous east winds, though these are short-lived. 



Apart from wind dispersal of spores, vegetative repro- 

 duction tends to favour the same situations, south or 

 east, for south-west winds bring moisture, and, when not 

 laden with poisonous substances, are beneficial ; but long- 

 continued wind tends to drive plants to the east side, and 

 absence of sun from north to south. 



The causes inducing birds to nest preferably on the 

 eastern and southern sides of hedges (and trees, to some 

 extent) are much the same, i.e. protection from wind and 

 the greater safety of a leeward position and amount of sun- 

 light ; but in their case, also, there is light dispersal. 

 There is a shadow on the leeward side of hedges for a 

 great , part of the day after the early dawn, and this 

 enables birds safely to go in and out without being 

 observed. 



The western side presents fewer convenient nesting sites, 

 the : branches of hedges being generally bent over from 

 west to east,, as seen best on the west coast, affording a 

 better arbour on the east. The south and east face early 

 dawn longest, and this is the favourite season of the birds. 

 At any rate, their song is richest between 4 and 8 a.m. 

 The north and west are open to bright sun but during 

 the colder part of the day. 



As to the actual distribution of nests, the same positions 

 noticed by Lieut. -Colonel TuU Walsh are favoured by 

 birds in Leicestershire, Shropshire, Surrey, amongst other 

 counties, and seem to be more or less general. The need 

 for studying cryptogamic distribution in relation to wind 

 in connection with the extinction of plants led me to 

 formulate the conclusions noted. It is interesting to 

 observe that they are directly analogous to the position 

 of birds' nests in hedges. , Hence the parallel drawn. 



A. R. HoRwooD. 

 . Leicester Corporation Museum, December 22. 



Studies in Polychaet Larvae. 



M.^Y I make use of your columns to correct an error 

 in my " Studies in Polychast Larvse " in a recent number 

 of the 0.].M.S.? The specimen there described as a 

 young Odontosyllis sp. I have since found to be in reality 

 a fully grown Exogone. I have been unable to identify 

 it with any l^nown species, but as dorsal natatory seta; 

 are quite well known in specimens of Exogone of this 

 size, the conclusions drawn from this specimen are of no 

 value. 



With regard to the last section of the same paper, it 

 has lately come to my notice that de Saint-Joseph has 

 shown Ciaparede and Mecznicow's so-called Spionid larva, 

 in which there are no provisional setie, to be the larva of 

 the aberrant worm Saccocirrus, and not of one of the 

 Spionidae. There is, then, no known exception to the rule 

 .that free-swimming Spionid larvae bear provisional set^. 



F. H. Gr.-welv. 



5 .Silver Street, Wellingborough, December 27, 1909. 



Cross-fertilisation of Sweet-peas. 



I HAVE recently seen two further reiterations of the state- 

 ment that the sweet-pea is invariably self-fertilised, a state- 

 ment which I think is often based on an opinion of 

 Charles Darwin's. It may therefore be worth while 

 placing on record an observation made by me in 1907, 

 when examining daily and closely a large quantity of 

 sweet-peas. While Apis mellifica failed entirely to open 

 the flower, it was done perpetually by Megachile 

 willughbiella, and there was not the least doubt about the 

 cross-fertilisation being effectively brought about by this 

 bee. The point has probably been noted before, but it is 

 worth recording once more in view of the repetition of 

 statements as to the self-fertilisation of sweet-peas. 



jr. 



NO. 2097, ■VOL. 82] 



A Supposed New Mineral, 



When we wrote recently (Nature, October 28, 1909) 

 about a supposed new mineral from Co. .'\ntrim, we were 

 led to believe that the specimen we had received was 

 from the basalt — our information, in fact, was that " a 

 very big pocket of it " had been found in that rock, but 

 the exact locality could not be ascertained at that time, 

 the finder having left home. 



We now hear that this gentleman cannot remember 

 where he got the specimen. It certainly cannot be traced 

 to the basalt, and as its composition is unlike that of any 

 known mineral, it seems highly probable that the substance 

 is an artificial product. 



Richard J. Moss. 

 Henrv J. Seymour. 



Laboratory, Royal Dublin Society, 

 December 23, 1909. 



THE HE.ART OF ANTARCTICA.' 

 IMMEDIATELY after the arrival of the British 

 ■•■ .Antarctic Expedition of 1907-9 in New Zealand 

 the attempt was made in Nature (April i, 1909, vol. 

 lxx>-.., p. 130) to e.stimate its scientific results from the 

 information received by cable. The full details now 

 supplied show that the estimate then made in no way 

 exagfjerated the greatness of its achievements. The 

 full story of the expedition, told in these most interest- 

 ing and beautifully illustrated volumes, shows that 

 its great success was due to careful and scientific fore- 

 sight in equipment, to the determined and uttermost 

 use of the equipment and staff, and to daring in the 

 field, carried sometimes to the verge of recklessness, 

 but saved from accidents by sound judgment and coo! 

 courage. 



The main purpose of the expedition was to reach 

 the South Pole, and as that object required an advance 

 into the heart of Antarctica, no better route could 

 have been selected. There can be little doubt that the 

 expedition would have been completely successful and 

 reached the Pole but for the accidents to the ponies. 

 Four of them died in the winter quarters, one from 

 eating some poisoned shavings, and three from eating 

 sand — perhaps due to the craving of horses for salt, 

 that m.ny not have been adequately allowed for in their 

 food. The most irreparable accident was the loss of 

 the last pony during the southern sledge journey by 

 its fall into a crevasse on the Beardmore Glacier. 

 The sledge party was thus deprived of an important 

 part of its reserve food, and the accident w-as especi- 

 ally annoying, as the pony was to have been killed 

 that night. The horse meat was not a complete suc- 

 cess, as it brought on dysentery. Sir Ernest Shackle- 

 ton explains this somewhat unexpected result by the 

 meat being poisoned by a toxin of exhaustion. As the 

 symptoms of fatigue can be transmitted by inoculation 

 from a tired to an untired dog, the suggestion sounds 

 probable. 



The work is prefaced by an admirable introduction 

 bv Dr. Mill on previous Antarctic work. The first 

 volume describes the equipment, the vain attempt to 

 land on the eastern side of the Great Ice Barrier, the 

 establishment of headquarters on MacMurdo Sound, 

 and the winter's work there. The motor car proved 

 of great service around the station, but though it 

 ran well on smooth sea ice, it would have been of no 

 use on the soft surface of the Barrier. 



The great sledge journey to the south was, there- 

 fore, dependent upon the ponies ; and these did their 

 work well. The sledging party consisted of Sir 

 Ernest Shackleton, Adams, Wild, and Marshall, with 



1 " The Heart of the Antarctic. Being the Story of the British Antarctic 

 Expedition, 1907-9." By .Sir E. H. Shackleton, C.V.O. With an Intro- 

 duction by Dr. Hugh Robert Mill. Vol. i., pp. xlviii-(-372 ; 132 plate^ 

 Vol. ii., pp. xvi + 4ip ; 141 plates, 3 maps. (London : W. Heinemann, 1909-) 

 Price, 2 vols., 36.?. net. 



