1869.] Botany and Vegetable Physiology. 101 



works at Cambridge, and possibly certain boat-loads of foreign 

 phosphate may have been brought by Upware thither. 



New British Seaweed. — Mrs. Alfred Gratty has fomid in 

 Cardigan Bay, and Dr. J. E. Gray has described in the Ann. and 

 Mag. Nat. Hist. Elachista stellaris. — There are eight other British 

 species of Elachista, which Dr. Gray arranges in three groups. 

 Mrs. Gatty also found Gigartina 'instillata in fruit in Blackpool 

 Bay. The late Dr. Harvey saw the specimen, and recorded it in 

 the herbarium of Trinity College, Dublin. 



Palu. — Some time ago a very small quantity of a fine silky 

 substance was brought to England from California under the above 

 name, and it was used as an object for the microscope, on account of 

 its beautiful structure. Mr. Bingham, in his very interesting 

 paper "On the Volcanic Phenomena of the Hawaiian Islands," says,' — 

 " JPalu is the silky covering of the opening fronds of several species 

 of tree-ferns, and is exported in large quantities to Cahtbrnia, for 

 beds,* &c," The trade is so extensive that " corduroy roads " are 

 made to the station where it is collected, and whole districts are 

 leased for the " Palu business," and there is a large number of 

 " Palu pickers." The Palib is collected at Kelanea, which is the 

 most tropical region in Hawaii. The tree-ferns have stems 15 feet 

 high to the base of the frond, and 8 or 12 inches in diameter. 



Plants without Boots. — The French Academy has received a paper 

 from M. Duchartre on certain plants which vegetate without roots. 

 In South America people will suspend such plants from a balcony 

 by a thread, without their being in contact with anything else, and 

 yet they will grow and blossom in this strange position. In our 

 hothouses we see them, simply stuck upon a piece of wood or cork, 

 thrive beautifully without any roots. The question therefore is, 

 How do they live ? M. Duchartre, to discover the secret, has in- 

 stituted a series of experiments on a plant of this family — the 

 Tillandsia dianthoidea. Tv/o tolerably equal sprigs of it, without 

 a vestige of roots, were tied separately to two slices of dry cork 

 from the same piece. They were then freely suspended in the air, 

 and weighed from time to time. One of these plants. A, never got 

 any water at all ; the cork of the other, B, on the contrary, was 

 moistened every second or third day. After the experiment had 

 been continued 103 days, A had lost one-third of its weight, but 

 had nevertheless produced blossoms and a small root; B, on the 

 other hand, was extremely vigorous, and had increased one-eighth in 

 weight. M. Duchartre thence concludes that these plants require 

 water, but do not absorb the moisture of the atmosphere. 



Beproduction of the Diatomacese. — In the last number of the 

 ' Quarterly Journal of Microscopical Science ' Count Castracane 



* P. 426. 



