SCIENCE- G OSSIP. 



of records. Any of the readers of SCIENCE-GOSSIP 

 who may have Swiss gatherings of this group, 

 either named or non-named, would greatly oblige if 

 they would communicate with the writer. — James 

 Saunders, A.L.S., Luton, England. 



Mosses New to Ireland. — The Rev. H. W. 

 Lett, M.A., records, apparently for the first time, 

 three species of mosses that have been found 

 in Ireland. They are Campylopus sha/mii, from 

 Co. Cork ; C. soMmperi, from Co. Kerry ; and 

 Dicranvm wneinatum, from Co. Mayo. These are 

 interesting on account of their extended range in 

 the British flora, all three species having previously 

 been only known to occur in a few localities in 

 Scotland. 



Teaching op Botany. — In the October number 

 of •' l'he Record of Technical and Secondary 

 Education " is an exceptionally interesting illus- 

 trated article by Miss Ethel A. M. Webb with 

 regard to the teaching of botany in schools. It is 

 one of a series of articles on " Nature, Knowledge 

 Schemes " and the utilisation of museums. In this 

 article Miss Webb describes a successful experi- 

 ment at Warrington, where object-lessons are 

 arranged for the guidance of children, and been 

 largely appreciated not only by them, but also by 

 many of their elders. 



STRUCTURAL and PHYSIOLOGICAL BOTANY. 



CONDUCTED BY HAROLD A. HAIG. 



Recent Research on Centrosomes. — Pro- 

 fessor Bernard (Recherches sur les Spheres attrac- 

 tives chez Liliiim ca/ndidwni, Helosis giiayanensis, 

 etc., "Jour, de Botanique," September 1901) is 

 convinced of the presence of centrosomes in Lilhirn 

 candidum and L. martagon In the former they 

 were found quite regularly during the various 

 phases in germination of the megaspore. They 

 were also observed in gametophytes of Helosis ; 

 and, moreover, the centrosomes appear to be cyto- 

 plasmic in origin. In the same paper it was 

 pointed out that there are occasionally two embryo- 

 sacs in L. eandidvm. This would, of course, be the 

 result of the further division of the original cell of 

 the archesporium, which usually goes to form only 

 the single megaspore. The paper in question does 

 not state whether both embryo-sacs contain potential 

 nuclei, capable of undergoing the usual changes 

 subsequent to fertilisation, but it may fairly be 

 assumed that only one is a potential embryo-sac 

 if the analogous phenomenon of polyembryony 

 holds good in this respect. 



Material for Study op Cambium. — In 

 Dicotyledons and Gymnosperms the study of the 

 ring of meristem that occurs between the xylem 

 and phloem — in other words the cambium — is of 

 great importance in relation to the formation of 

 the secondary phloem and xylem. Another interest- 

 ing point is the consideration of the origin of the 

 interfascicular cambium by the extension of the 

 ring between the primary bundles, thus ulti- 

 mately giving rise to secondary bundles. It is no 

 (asy matter to select good material for the pre- 

 paration of sections, either transverse or longi- 

 tudinal. It is only by the careful preservation of 

 such material in suitable hardening or fixing re- 

 agents that we are enabled to keep it in good 

 ■'cutting" order, by which is meant that the 

 tissues must be neither too hard nor too soft, yet 



retaining their original bulk, with little or no con- 

 traction. For this purpose a 2 per cent, solution 

 of osmic acid is a very good preservative and 

 hardening reagent ; but even in this some of the 

 more delicate tissues, notably the cambium, get 

 brittle after long standing. We are inclined to 

 the belief that ordinary alcoholic spirit forms a 

 very fair preservative for most vegetable tissues, 

 and certainly the results hitherto obtained have 

 served to strengthen this belief. The actual 

 selection of material is to be taken more or less 

 hand in hand with the practically tested degree 

 of contraction experienced by that material when 

 placed in the preserving medium. It is no use 

 studying cambium in plants that experience great 

 contraction on fixing, such as do most succulent 

 plants which contain a large amount of cell-sap. 

 The best thing is to select plants having a liberal 

 amount of pith in the centre of the stem, so that 

 if any contraction is to occur it may have some 

 resistance to contract against. In this way the 

 contour of the stem is preserved, and this is not 

 the least important point in the preservation of 

 the cambial ring. We have found young shoots of 

 the hop plant (LujjuIus) give very satisfactory 

 results in this respect, as there is a good central core 

 of growing pith which certainly aids in preventing" 

 the outlying tissues from contracting very much 

 Sambumts (elder tree) is another good plant in 

 which to study the cambium, and in sections of 

 young shoots that have been treated with eau de 

 Javelle previous to staining very fine results may 

 be obtained. The sunflower gives fairly good re- 

 sults with sections of the stem ; but in this case 

 the presence of very hard bands of sclerenchyma. 

 situated at various points of the circumference, 

 make it difficult to get good sections, seeing that 

 the razor is a little blunted before it even gets to 

 the cambium. The main points, then, to be ob- 

 served are: (1) Select material that will not suffer 

 much contraction in keeping in the preservative 

 medium ; (2) ascertain by test sections that there 

 are no mechanical difficulties in the cutting of the 

 section, such as would be produced by hard bands 

 of sclerenchyma ; (3) take a plant in which the 

 cambial ring is of fair extent in the radial 

 direction. 



Ciliary Action in Plants. —Amongst the 

 Thallophyta (Protococcaceae) we find minute 

 organisms which are endowed with the power of 

 motion. Such are Protoeoocus, Cldamydomonas, 

 and some others. As is well known, they owe this 

 power to the possession of cilia, which in some 

 cases are so long as to deserve the term "flagella " 

 being applied to them. If we observe carefully 

 under a microscope one of these organisms — in the 

 case under examination it is 8pltarrella—\ve find 

 that, unless the light is regulated by means of the 

 condenser until a semi-dark field is produced, we 

 can see little or nothing of the to-and-fro lashing 

 movements of the two cilia situated at the so-called 

 " anterior pole " of the organism. Having, how- 

 ever, stopped down the iris diaphragm to very 

 nearly its limit, we can occasionally catch sight 

 of them — that is, when the organism is more or 

 less stationary, or only rotating. The flagella in 

 the case examined are very long and delicate, and, 

 if carefully fixed and stained preparations are 

 made, can be seen under a high magnification to 

 be processes of the outer protoplasmic lining of 

 the organism that lies next the cell-wall ; in other 

 words, the " ectoplasm." The rate of movement of 



