Vol, III. No. 52. 



THE AGRICULTURAL NEWS. 



123 



SCIENCE NOTES. 



A Weather Plant. 



About tliirteen years ago il. Nowack, an Austrian, 

 described a 'Weather ulant' sui)iio.sed to have been discovered 

 by him. The i)lant in (juestion proved to be what is known 

 in the West Indies and elsewhere as the ' Crali's Eyes.' It 

 is a slender vine with pinnate leaves, producing .small, bright^ 

 red seeds with a black spot. The .scientific name is Abrus 

 jjrecaton'ux. The first name was given on account of the 

 softness of the leaves, and the second (prayer or paternoster 

 pea) because the bright-coloured seeds were sometimes used 

 as a rosary. 



M. Nowack claimed that by closely watching the 

 changes that took place in the position of the leaves and the 

 rise and fall of the twigs and branches he could predict 

 'changes in the weather and also the occurrence of earth- 

 quakes.' After a full and careful investigation made at Kew 

 and elsewhere, Professor ¥. W. Oliver was in a position to 

 show, conclusively, that the ' Crab's Eyes ' plant only ■ 

 exhibited the usual sleep-movements commonly noticed in 

 tropical vegetation and that there was no connexion 

 existing between these movements and changes in the 

 weather or the occurrence of earthquakes. 



There appears to be a revival of interest in this matter. 

 It is observed that the subject was recently discussed at a 

 meeting of the Society of Arts in London, but ajiparently no 

 new facts were brought forward in support of the claims 

 advocated by !NL Nowack. 



Those interested in the subject will find full information 

 and a detailed account of the investigations above referred to 

 in the Kew Bulletin (1890, pp. 1-28). 



Propagation of Plants by Leaves. 



Herr Lindemuth of Berlin, has published in Oaftenfioni 

 (1903, Heft 18 and 23) the results of his experiments on 

 the propagation of plants by means of their leaves. Horti- 

 culturists have long been accustomed to use this means of 

 propagation in a few plants, notably in the Gloxinin and 

 certain Crassii/aceae, among which Bryophyllum, calyclnum 

 [Leaf of life] is a well-known example. It was, however, 

 probably not suspected that the leaves of so many plants 

 could be made to jiroduce roots. In his first communication 

 Herr Lindemuth gives the names of twenty-eight species, of 

 nearly as many different genera, in which his experiments 

 have been successful. These include such plants as the 

 foxglove (Digitalis purjmreii), the musk (Mimuhis moscliat m), 

 the tomato and the vine. The leaves of tliirteen species, 

 including the potato, monkshood {Aronitiaii Napellua) and 

 the common bedding geranium (PelmyoHium zoiinle) refused 

 to root at all. 



Usually the roots were produced fjuickly — ii\ the vine in 

 sixteen days, in Veronica in seven days, and in the African 

 marigold in eight dajs — but the amount of time required, 

 and, indeed, success at all, was shown to depend very much 

 on the season when the experiments were made. Thus, in 

 the vine roots were developed in sixteen days i)i August ; 

 but complete failure resulted in Sei)tember when the leaves 

 peri.shed. In his second communication, the author records 

 success with thirty-four additional species, including three of 

 those with which he had met with failure before. The 

 results so far obtained show that few of the leaves thus 

 experimented on will form buds, only five having done so. 

 (S. A. iS. in Knowledge and Scientific Neivt, JIarch 1904.) 



Yeast. 



Yeast is a substance, the uses of which for domestic 

 purposes and in brewing, etc., are well known. Yeast itself 

 is a i)lant belonging to the group of fungi. 



The yeast plant, Saccha ram yets, differs from most other 

 fungi in that its body consists of a single cell ; it is probable 

 that the yeast is a reduced form, being descended from 

 ancestors which possessed a mycelium. 



When brought into a proper nutrient medium, such as 

 a .sugar solution containing ammonium tartrate (as a source 

 of nitrogen) and minute quantities of mineral salts, yeast 

 proceeds to reproduce. The process is one of budding. 

 A small bulge api)ears atone side of the cell, which increases 

 in size until it is the same size as the parent cell and is then 

 cut off; the daughter cell then rei)eats the process. Sometimes 

 the budding proceeds so i-ajiidly that both the daughter and 

 mother cells start budding again before they become sepa- 

 rated ; in this way we get short chains of cells, each one of 

 which, however, is a distinct plant. The spores of many 

 other fungi are capable of rei)roducing in this way, by budding, 

 but the buds so produced are cajiable, given the proper 

 conditions, of giving rise to a hypha and so to a mj'celiuni. 

 The yeast buds have never been made to produce a hypha. 

 Under certa,in conditions the yeast plant i)roduces spores. 

 We can make it do this by cultivating it until it is growing 

 vigorously and then spreading it out in a thin film on the 

 surface of a plaster of Paris plate ; damp air is continuously 

 passed over the plate. In twenty-four hours the cell contents 

 become finely granular, next we notice four liright points 

 apjiearing in the cell, and finally the cell contents group 

 themselves around these, and separate oft" to form four 

 ' endospores', arranged in a tetrad inside the old wall of the 

 mother cell. 



Ordinary brewers' yeast is a mixture of various species 

 of yeast ; some of these do not bring about alcohfilic fermenta- 

 tion, and are either useless or positively harmful. In this 

 lies the advantage of using only pure cultures of i)articular 

 yeasts, which are known to bring about the desired fermenta- 

 tions. This method is now used in ui)-to-date breweries. 



DEPARTMEMT NEWS. 



Mr. George Whitfield Smith, Travelling Superin- 

 tcMiilent on the stall' of the Imperial Department of 

 Agriculture, has been appointed by the Secretary of 

 State for the Colonies to the post of Magistrate for the 

 Northern District of Grenada, to reside at Carriacou. 

 In view of the important agricultural efforts to be 

 carried on there and the value attached to the 

 successful working of the Land Settlement Scheme, 

 Mr. George Whitfield Smith's appointment is calculated 

 to prove of great service in advancing the general 

 interests of that island. 



The Secretary of State has approved of the 

 appointment of Mr. William Henry Patterson as 

 Curator of the Botanic and Experiment Stations at 

 Antigua in succession to Mr. W. X. Sands, who has 

 been recently transferred to St. Vincent. Mr. Patter- 

 son was sub-foreman at the Royal Gardens at Kew and 

 j)reviously for three 3'ears had been employed in the 

 County Technical Laboratories at Chelmsford. His 

 wife is also a skilled horticulturist, trained at Kew. 

 Mr. and Mrs. Patterson are due to arrive at Antigua 

 in the mail of April 13. 



