liS 



NA TURE 



[August 6, 1908 



section on agriculture is one of tlie best in the book, 

 but even iiere tliere are many signs of tlie eflort 

 whicli lias been exerted in writing short popular 

 descriptions. 



It is to be feared that the book will fall between 

 two stools. It is too dry and unattractive for the 

 ordinary traveller, whilst the serious student will not 

 find it satisfactory. 



Dr. Willis would have been better advised had he 

 devoted himself to preparing a more serious work, or, 

 if time did not permit of this, to producing a new 

 edition of Sir Emerson Tennent's standard treatise. 

 The present work is not likely to add to his reputa- 

 tion. 



The Royal Gardens, Kcii.'. From photographs taken 

 by permission. By E. J. Wallis, with descriptive 

 notes by H. Spooner. Pp. 64. (London : E. J. 

 Wallis, 42 Gloucester Road, Kew Gardens, n.d.) 

 Price IS. net. 

 It is difficult to realise that the modern development 

 of Kew Gardens as a public institution only dates back 

 to the middle of the last century, when Sir William 

 Hooker initiated the extensions and improvements that 

 have been continued by his successors in office. In- 

 creased travelling facilities in recent years have largely 

 augmented the number of visitors to Kew, and con- 

 sequently there is certain to be a large demand for a 

 popular account of the gardens that will serve as a 

 memento of what must often be memorable visits. 

 The illustrations provided by Mr. Wallis depict ex- 

 teriors and general views, selected spots in various 

 houses, and a few specimen plants. The photographs 

 of the tropfcal water-lilies and of the Yulan, Magnolia 

 conspicua, are especially pleasing, also of the delicate 

 flowers Cypripcdinm glaucopliylluin and Pcristcria 

 data. Mr. H. Spooner has contributed the text, in 

 which strangers will find a useful guide round the 

 houses and to the choice specimens, as well as brief 

 descriptions of the more regular and conspicuous 

 tenants. 



LETTERS TO THE EDITOR. 



[The Editor does not hold himself responsible for opinions 

 e.\pressed by his correspondents. Neither can he tindertaki 

 to return, or to correspond with the writers of, rejectee 

 manuscripts intended for this or any other part 0/ Nature, 

 No notice is taken of anonyutous contDitinications.] 

 The Ciliated " Urns " of the Sipunculids. 

 In the winter of 1S71-2 I studied the richly rorpuscu- 

 lated perivisceral fluid of Sipiinculus nudus at Naples. 

 I was with Anton Dohrn, who was making arrangements 

 for the building of his celebrated laboratory. That remark- 

 able marine zoologist Krohn, who in 185 1 had described the 

 ciliated " urns " (Topfchen) of the body-fluid of Sipunculus 

 as parasites, was there, and spent an evening with us. I 

 described the ciliated urns briefly in the .innals and Mag. 

 of Nat. Hist., vol. xi. (fourth series), 1873, p. 89, and 

 pointed out their mode of origin. I say, " Further, I 

 have found out the source of the ' Topfchen.' They are 

 to be observed in great numbers attached u'iOm'ii the curious 

 pair of tubes or vessels formed by duplicatures of the peri- 

 toneal membrane, which lie on each side of the 

 cesophagus." I then give a wood-cut figure of the 

 attached " urns " with long stalks, and state that " they 

 develop as buttons on the cellular surfacp," and that " they 

 become detached and swim off into the fluid." 



This statement was erroneously quoted nearly thirty 

 years after its publication, in the first instance by Cuenot, 

 who said that I stated that the urns were developed on 

 the outside of the oesophageal tubes, whereas I had 

 italicised my statement as above to the effect that they 

 are developed on the inside of those tubes. 



The matter is not one of great importance, but it is 

 not agreeable to see a statement repeated to the effect 

 that one said just the opposite of what one did say. This 

 repetition of an error is made by Dr. Selensky, of St. 



NO. 2023, VOL. 78] 



Petersburg, in the Zeitschr. f. Tjniss. Zoologie, Bd. xc, 

 p. 55S. He apparently has not consulted my paper, 

 but, although he does not say so, has taken his 

 information from Cuenot, to whom, erroneously, he 

 attributes the first correct observation as to the place and 

 mode of origin of the ciliated urns of the Sipuculids, 

 an observation published by me now thirty-five years ago. 

 1 wish clearly to state that I am quite sure that neither 

 Prof. Cuenot nor Dr. Selensky had any notion that they 

 were not quoting me correctly. I should have let the 

 matter pass altogether had there not been lately an attempt 

 to revive tlie notion that these curious freely swimming 

 corpuscles with their crown of cilia are parasites. I dis- 

 posed of that hypothesis when 1 observed in 1S71-2, and 

 figured in 1873, their mode of growth. 



E. Rav Lankester. 

 39 Thurloe Place, S.W'., July 30. 



Prominence and Coronal Structure. 



Communications by Ur. Lockyer and by Mr. Buss have 

 appeared in recent numbers of Nature (April 2, June 18, 1 

 and June 25) under the above heading. In the last- 

 mentioned number Dr. Lockyer quotes a portion of a 

 letter which I wrote to him following the publication of 

 his original paper, showing the triple-arch prominence. 

 I examined my plates under very unfavourable illumina- 

 tion, and wrote that no prominence of unusual form was 

 discernible in the position which he gave. More careful 

 examination shows a faint, detached, V-shaped cloud 

 attaining an elevation of 67,000 miles, as probably the 

 last remnant of the prominence, at considerable elevation. 

 The accompanving figure will show this faint cloud at 



■4b°-S- 



I regret that Dr. Lockyer did not quote my letter 

 further, for I wrote that I had so often seen a promin- 



ence, risen to considerable height, topple back into the 

 sun, thus making an arch, that it seemed unwarrantable 

 to assume another explanation for their formation without 

 positive knowledge that the earlier stages of development 

 were contrary to this usual performance. Fortunately, 

 Mr. Buss had earlier observations of this prominence, and 

 these showed the arches to have had the usual origin. 



Concerning the prominence in the south-western 

 quadrant. Fig. 2 of Dr. Lockyer 's letter, for which he 

 suggests the possibility of false orientation on my print, 

 the present figure shows that the orientation was correct. 

 The part of the prominence corresponding to the promin- 

 ence at 218" shown on the negatives of Dr. Lockyer and 

 of Prof. Hale is easily recognised at 2i9°-3. The long arm 

 springing for position-angle 208° is apparentlv a new 

 development. Philip Fox. 



Verkes Observatory, July 18. 



Fossil Aphididae from Florissant, Colorado. 



The plant-lice of the Miocene shales at Florissant, 

 Colorado, have been described at length by Scudder in his 

 great work on Tertiary insects (1890). He was able to 

 recognise no fewer than fifteen genera and thirty species. 

 .Ml the genera were considered to be extinct, and 

 although they included both .'\phidina; and Schizoneurinae, 

 they were found to differ from the modern representatives 

 of these subfamilies in an important character running 

 throughout the series — the length and slenderness of the 

 marginal or stigmatic cell. In this they also differ from 



