August 20, 1891] 



NATURE 



371 



"Bibliotheca Botanica," illustrated by eleven fine plates, by 

 Herr G. Karsten. Herr Karsten points out that, in addition to 

 the obvious mechanical function of these roots, serving as a 

 supporting organ to attach the trees more firmly to the very 

 loose soil in which they grow— this is especially observable in 

 Khizophora mangle— \.\\txt is another important function per- 

 formed by them, at least in a large number of the trees which 

 make up the mangrove- vegetation, though I do not recollect 

 that Avicennia uivca is especially mentioned. In the species 

 examined by Karsten, these aerial roots possess very large inter- 

 cellular spaces, which serve to promote the interchange of gases ; 

 and he considers it unquestionable that their chief function is to 

 assist respiration. He therefore proposes for them the term 

 " pneumatophores." It would be interesting to examine the 

 structure of the trees at the Botanic Garden in this respect. 

 All mangrove-trees also contain large quantities of tannin, which 

 is probably serviceable in preventing rotting. 

 August I. Alfred W. Bennett. 



The Tasman Sea. 



I SEND you the inclosed copy of a letter from the Secretary 

 of the Admiralty, in case you should consider the matter of 

 sufficient interest for notice in your columns. 



A. LiVERSiDGE, Permanent Hon. Sec. 

 Australasian Association for the Advancement 

 of Science. 

 The University, Sydney, July 4. 



Admiralty, May 19, 1891. 

 Sir, — With reference to your letter of March 17, forwarding 

 copy of a resolution passed by the Australasian Association for the 

 Advancement of Science at the meeting held at Christchurch, 

 New Zealand, that the name of Tasman Sea should be given to 

 the sea between New Zealand and the islands of the north-west 

 of New Zealand on the one hand and Australia and Tasmania 

 on the other, I am commanded by my Lords Commissioners of 

 the Admiralty to acquaint you that the name will be inserted in 

 Admiralty charts and other publications. 

 I am. Sir, 



Your obedient servant, 



Evan MacGregor. 

 To Prof. Liversidge, M.A., F.R.S., 

 The University, Sydney. 



Reduplication of Seasonal Growth. 



Last summer I sent you a note on the occurrence of apple- 

 blossoms and the blossoms of the mountain ash in July. Before 

 me now, as I write, is a simple but elegant bouquet containing 

 a beautiful and fragrant corymb of the latter tree in full flower, 

 side by side with one of the ripe scarlet fruit, which the black- 

 birds have begun to devour. These were cut from one and the 

 self-same tree this morning at the top of my garden ; while from 

 an adjoining tree was gathered a twig carrying four pinnate 

 leaves from which all the chlorophyll has disappeared ; the 

 phenomena which mark the beginning and the end of the season 

 thus appearing side by side. These trees grows on the Upper 

 Bagshot Sands, and I have no doubt that this reduplication of 

 seasonal growth is due to the later rains developing some centres 

 of flowering energy in the plant, which had remained dormant 

 during the spring owing to deficiency of moisture and warmth. 



Wellington College, Berks, August 17. A. Irving. 



Rain-gauges. 



I have been using the ordinary Symonds pattern rain-gauge, 

 but find that the percentage of rain collected varies in propor- 

 tion to the strength of the wind ; when this is moderately 

 strong, almost the whole of the rain passes across the top. 

 strikmg and being retained by vertical surfaces only. 



The present method of estimating the rainfall is far from 

 being either correct or uniform, and I should like to ascertain if 

 any gauge has been made with a correctly-proportioned inverted 

 cone, which will collect and compensate for side drive ; and, if 

 so, what are the correct proportions. It would appear that 

 either this, or a funnel mounted on gimbals and balanced to face 

 the wind at the correct angle, must be the only correct method 

 to ascertain the actual ramfall. The present apparatus would 

 appear to be crude, untrustworthy, and incapable under any 



conditions in practice of giving results which are at all trust 

 worthy. Thos. Fletcher. 



Grappenhall House, Grappenhall, near Warrington, 

 August 17. 



THE BRITISH ASSOCIATION. 

 (from our correspondent.) 



Cardiff, Wednesday Morning. 

 T^HE preparations of the Local Committee are now in 

 ■*■ an advanced state, and members of the Association 

 are beginning to arrive in considerable numbers. 



A change has been made in the position of the Recep- 

 tion Room, which is now located entirely in the Drill 

 Hall, the Town Hall having had to be abandoned for that 

 purpose owing to the impossibility of making adequate 

 provision for the accommodation of the large number of 

 guests expected The Drill Hall is a large building, and 

 ' has been divided into two parts by a screen, which also 

 serves the purpose of a notice-board. On the entrance 

 side are the offices for various purposes, post and excur- 

 sions ; and at a central oval counter, all other requirements 

 relating to tickets, reserved seats, publications, and lodg- 

 ings are attended to by a numerous staff of clerks. 



Beyond the screen the hall has been fitted up as a 

 drawing-room, and from this lead off smaller rooms for 

 ladies, the press, and smokers. Separated from the 

 drawing-room by a passage is the gun-room, from which 

 everything has been removed, and tables laid down so as 

 to convert it into a dining-room. 



The President's address will be given in the Park 

 Hall, this evening, and for the half-hour of waiting 

 before the business commences Mr. T. E. Aylward will 

 give a recital upon the fine organ in that hall. It is 

 understood that Lord Bute, as Mayor of Cardiff, will at 

 the outset welcome the Association in the name of the 

 town of Cardiff. 



The conversazioni will also be given in the same 

 hall, and from 8.30 to 9 p m., Lord Bute, as Chairman 

 of the Local Committee, accompanied by Lady Bute, 

 will receive the guests. At 9.30 p.m. an exhibition of 

 views will be given by the lime-light, amongst them some 

 fine ones, by Mr. M. Stirrup, of the limestone region of 

 Languedoc. Amongst other attractions will be taking 

 impressions of finger-tips, by Sergeant Randall (Mr. F. 

 Galton's assistant) ; a model of the moon, sh own by the 

 Astronomer-Royal of Scotland ; drawings in black and 

 white of the Himalayas, by Col. Tanner; a collection of 

 old local maps and atlases, by Mr. O. H. Jones ; the 

 Eisteddfod concert given at Swansea transmitted by 

 telephone, by Mr. Gavey ; and numerous other objects 

 of interest. 



Arrangements have been made for military and •vocal 

 music. 



No alteration has been made in the Section rooms 

 from that mentioned in our former article. 



The publications of the Local Committee are ready for 

 distribution, and comprise the local hand-book of 240 

 pages dealing with the archaeology of the land of Morgan, 

 the education, botany, geology, industries, and topo- 

 graphy of Cardiff ; the excursions-guide containing a map 

 of the district on a scale of four miles to the inch, and 

 two maps on a larger scale, one of the Bute Docks, and 

 the other of the Barry Dock. The excursions number 

 twenty in all— twelve are arranged for Saturday, the 22nd, 

 and eight for Thursday, the 27th ; and moderately detailed 

 descriptions of each are given in the guide to the 

 excursions. 



The local programme, and the list of lodgings and 

 hotels, are the remaining publications of the Committee. 

 The total number of members of all classes who have 

 taken out tickets for the meeting was, at 6 p.m. yesterday, 

 over 900. 

 The President's address is as follows : — 



NO. 11.38, VOL. 44] 



