566 



NA TURE 



[October 6, 1904 



ditioiTc of the climate, not an active one corresponding to 

 the views of the Lamarclvians. 



Mr. Francis J. Lewis presented a paper on the inter-Glacial 

 and post-GIacial beds of the Cross Fell district, in which 

 he pointed out that the plant remains are of considerable 

 interest as throwing' light upon the duration and climatic 

 conditions of the several Glacial and inter-Glacial periods. 

 The plant remains of the post-Glacial peat also show that 

 considerable fluctuations have taken place in climate since 

 the close of the Glacial period. 



Morphology {including Palaeobotany). 

 Dr. D. H. Scott, F.R.S., described a new type of 

 sphenophyllaceous cone from the Lower Coal-measures ; the 

 cone shows the anatomy and general organisation character- 

 istic of the group, but is distinguished by its branched 

 sporangiophores terminating in peltate, bisporangiate 

 scales, and by the absence of any sterile appendages. 



In conjunction with Mr. E. A. Newell Arber, Dr. Scott 

 also presented a short account of two new Lagenostomas. 

 In one of them, L. Kidstoni, the seeds are naked, but in 

 the other, L. Sinclari, there are indications of an extsrnal 

 envelope or cupule. The new seeds were apparently borne 

 on the ultimate branches of a frond in which the lamina 

 had been greatly reduced. There are indications that the 

 fronds were of the Sphenopteris type. 



Prof. C. Eg. Bertrand (Lille) contributed a paper by 

 Prof. Cornaille and himself on " La structure de la trace 

 foliaire des Filicin^es inversicatenates." 



Miss Sibille O. Ford gave an account of the anatomy of 

 Psilotum triquetriim, from which she concludes that the 

 Psilotaceas not only present an affinity with the fossil 

 Sphenophyllales, but also have a strong resemblance, 

 anatomically, to some of the fossil Lycopods, especially to 

 the stem of Lepidodendron mundum, as well as to the axis 

 of the cone of Lepidostrobus Brownii. 



Mr. T. G. Hill, in a paper on the presence of parichnos 

 in recent plants, pointed out that in the mature sporophyll 

 of Isoctcs Hystrix in the lateral expansions of its base are 

 two longitudinal mucilage-containing cavities which arise 

 by the mucilaginous degeneration of two strands of paren- 

 chyma. He suggests that this represents the parichnos 

 occurring in Lepidodendron, Sigillaria, Lepidocarpon, &c. 



Dr. Marie G. Stopes described her recent observations on 

 some new points observed in the ovular anatomy and struc- 

 ture in the different genera of Cycads, with the conclusion 

 that there are well marked indications of two integuments. 



Mr. L. A. Boodle read a paper on the reduction of the 

 gametophyte in Todea Fraseri. Owing to delay in the 

 dehiscence of the sporangium under certain conditions, many 

 of the spores germinate within it. The prothallus may 

 consist of only two or three cells with an antheridium. 

 This is of special interest when compared with the micro- 

 spores of Salvinia, as illustrating how a reduction of the 

 thallus of a fern approaching that shown by Salvinia may 

 be brought about by the non-dehiscence of the sporangium. 



Dr. William H. Lang, in a paper on the reduction of the 

 niarchantiaceous type in Cyathodium, concludes that it 

 appears probable that Cyathodium has been derived by 

 adaptation to damp and ill lighted situations from a well 

 characterised niarchantiaceous form of about the same grade 

 of differentiation as Targionia. 



Dr. J. P. Lotsy (Leyden), in an interesting account of 

 the virgin woods of Java, discussed the modifications pro- 

 duced in the vegetation by the two great forces moisture 

 and light, and proposed the use of a new term, biaio- 

 morphose, indicating that the form of each individual plant 

 is not a form innate to that plant, but is the result of its 

 specific structure and the sum of all external circumstances 

 which have acted upon it. 



Mr. E. A. Newell Arber presented a paper on a new 

 feature in the morphology of the fern-like fossil Glossopteris. 

 Dr. Otto Stapf exhibited and described the fruits of Melo- 

 canna, Melocalamus, and Ochlandra. 



Mrs. D. H. Scott gave demonstrations of kammatograph 

 photographs showing the opening and closing of flower 

 buds, the visits of insects to flowers, and other interesting 

 records of the movements of plants. 



Mr. Alfred P. Maudslay gave an account of some measure- 

 ments he had made of the great swamp cypress at Santa 

 Maria del Tule, Mexico. The area of a cross section of the 



NO 1823, VOL. 70] 



trunk of this tree, at a height of 6 feet from the ground, 

 is 408 square feet. 



Dr. K. C. Miyake (Tokio) read a paper on the centrosome 

 of the Hepaticae, from which it appears that it is very 

 doubtful whether centrosomes occur at all in these plants. 



Lord Avebury, F.R.S., in a note on the forms of the stems 

 of plants, brought forward the view that the shapes of the 

 stems of plants are dependent upon the arrangements of 

 the leaves, and the consequent distribution of the strengthen- 

 ing tissues in the stem so as to secure the greatest strength 

 with the least expenditure of materials. 



A short discussion on the present state of our knowledge 

 of the cell structure of the Cyanophycea2 was opened by 

 Mr. Harold Wager, F.R.S., who pointed out that the 

 central body of the cell must be regarded as a nucleus, but 

 that it is of a simpler or more rudimentary type than the 

 nucleus of the higher plants. 



Prof. E. Zacharias (Hamburg), whilst admitting that the 

 central body contains, under certain conditions, that essential 

 constituent of the nucleus, nuclein or chromatin, could not 

 accept the view that it is a nucleus, and especially objected 

 to Kohl's conclusion that it is a true nucleus in which both 

 chromosome and spindle formation fan be observed. 



Prof. R. Chodat (Geneva) considered that the central 

 body of the Cyanophyceae is merely a specialised region of 

 the cytoplasm in which granules of reserve substance 

 accumulate, and not of the nature of a nucleus at all. 



Mr. E. R. Burdon gave an account of the pineapple galls 

 of the spruce which are caused by the hibernating gener- 

 ation of certain Aphidse belonging to the genus Chermes. 



In the early stages the chlorophyll, tannin, resin, resin 

 canals, and secretory cells of every description disappear 

 within the gall area, which consists entirely of enormously 

 swollen parenchymatous cells. Starch is found in great 

 abundance round the periphery of the gall area, and it is 

 suggested that it may be the ultimate product of the dis- 

 integration of the tannin. 



The nuclei of the galled cells also become enlarged, and 

 the chromatin network becomes aggregated into numerous 

 wart-like nucleoli. The mitotic figures are of the usual 

 somatic type, and no indication of heterotypical mitoses has 

 yet been found. 



Mr. R. T. Baker exhibited specimens illustrating (i) the 

 comparative constancy of specific characters of Eucalyptus, 

 (2) the relation between the leaf venation and the oil con- 

 stituents. 



Prof. R. Chodat exhibited some beautiful examples of 

 pure cultures of algae, and Prof. G. S. West some photo- 

 micrographs of fresh-water plankton. 



Physiology. 



Dr. F. F. Blackman gave an interesting address on the 

 important investigations which have been carried on by 

 Miss Matthaei and himself on the question of sunshine and 

 carbon-dioxide assimilation. The address was illustrated 

 by a series of experiments, and the numerous elaborate and 

 ingenious pieces of apparatus which have been devised by 

 the authors for the automatic recording of the complicated 

 data required were exhibited and explained. 



Prof. S. H. Vines, F.R.S., gave an account of his re- 

 searches on the proteases of plants, the general occurrence 

 of which he has demonstrated in all parts of plants. They 

 are not of the nature of pepsin, but correspond rather to 

 either the trypsin or the erepsin of the animal body. 

 Trypsin and erepsin differ from each other in their capacity 

 for peptonising the higher proteids. Thus trypsin can 

 peptonise so complex a proteid as fibrin, whereas erepsin 

 cannot, though it can peptonise casein. It has been found 

 that in certain cases the juices or extracts of plants can 

 peptonise fibrin, indicating the presence of a tryptic pro- 

 tease ; but more commonly they do not possess this capacity. 



Prof. L. Errera (Brussels), in a paper on the localisation 

 of alkaloids in plants, pointed out that, although the 

 physiology of alkaloids is far from settled, a critical study 

 of their topography, as well as their behaviour in germin- 

 ation, growth, etiolation, maturation of seeds, &c., supports 

 the view that they are waste-products, resulting from the 

 catabolism of cytoplasm, and secondarily utilised for defence 

 against animals. A few grams of an alkaloid constitute a 

 protection not less efficient than the strongest spines. 



