January, 1911. 



KNOWLEDGE. 



25 



to our Unowledge of the mysterious laws which tjovern the 

 sidereal universe, I hope that some of them at least will .seize 

 this opportunity at once, and join the small band of observers, 

 to which I am proud to belong;, whose scientific activity is 

 greatly appreciated ; if not very fully in the British Isles, 

 at least elsewhere. ^^.^^^ ^^^^ ^^^.^ 



Honorary Secretary " Societc d' Astronomic d'Anvers." 

 ( To be cQiitimicd.) 



BOTANY. 



By Professor F. Cavers, D.Sc. 



SUSPENSOR IN FERN EMBRYOS.— It was recently 

 shown by Lyon that the enibr\'o of Botrychiiiiii obliqnuin 

 has a suspensor, while Campbell recorded a similar structure 

 in the case of Daiiaca. The interest of these discoveries lies 

 in the fact that hitherto a suspensor has only been known to 

 occur in the embryo of Lycopodiiiin and Sclaginclla among 

 the Fern Alliance, or Pteridophyta. Lang {.4//);. Bot.. 1910) 

 has just discovered that Hcliiiinfliusfachys, which is closely 

 allied to Botrycliiuiii. has a massi\'e suspensor liUe that of 

 the latter genus. 



THE ECOLOGY OF CONIFERS.— The ecological 

 features of the Coniferae are discussed by Groom (Ann. 

 Bot., 1910), who sets out various problems relating to this 

 interesting subject. The main questions are : (1) the cause of 

 the .xerophytic foliage and tracheidal wood; (2) the cause of 

 the survival of Conifers in competition with Dicotj'ledonous 

 trees; (3) the cause of the suppression of various Conifers in 

 past ages. Stress is laid on the fact that all Conifers are not 

 xerophytic, in spite of their xerophytic leaf structure. Hohnel 

 showed that the Larch has a rapid transpiration current, while 

 Groom's experiments show that Coniferous wood, in spite of 

 its tracheidal structure, may conduct water with a rapidity 

 equal to that of a rapidly transpiring Dicotyledonous tree. 

 Another point is noted in this connection — the aggregate leaf 

 surface of a Coniferous tree may exceed that of a Dicotyle- 

 donous tree, because of the immense number of the leaves. 

 This leads to the view that the .xerophytic structure of the 

 Conifer leaf is actually necessary because of the great amount 

 of exposed surface, and the term " architectural xerophytism " 

 is suggested for xerophytism that is dependent, as in this case, 

 upon the organization of the plant rather than upon the direct 

 influence of external factors on the organs in question. The 

 extinction of many of the ancient Conifers is attributed to 

 their imperfect acclimatization, to the fact that they have a 

 large number of insect and fungus enemies, and to their 

 relatively slight power to react advantageously to new con- 

 ditions. At the same time, their " architectural " xerophytism 

 enables them to thrive in nearly all situations, from those that 

 are physically or physiologicall>' dry to those that are 

 sufficiently humid to permit the development of luxuriant non- 

 xerophytic forests. 



"GERMANOL." — A Berlin syndicate has placed on the 

 market a product called " Germanol," consisting of an earthy 

 mixture containing about eighteen per cent, of calcinated soda. 

 The virtue of this mixture, which is intended for agricultural 

 use, is attributed by the manufacturers to an increased 

 porosity of the soil following an increase in the proportion of 

 carbon dioxide, the latter being supposed to act as a "fertiliser." 

 Mitscherlich (Landwirtscli. Jahrb., 1910) has made extensive 

 experiments, however, which appear to show that if this 

 mixture has any value at all it must be attributed to the action 

 of the carbon dioxide in increasing the solubility of difficultly 

 soluble substances in the soil. He concludes, moreover, that 

 increasing the carbon dioxide content of the soil does not 

 result in an increase of plant product ; that there is always 

 sufficient carbon dioxide in the soil already to render mineral 

 food available ; and that any increase in the solubility of soil 

 constituents due to increase on carbon dioxide content is 



absolutely superfluous so far as any advantage to the plant is 

 concerned. It would seem, therefore, that "Germanol" will 

 pro\e a failure in practice, just as various other nostrums, like 

 " Nitragin " and " Nitro-bacterine," have done in the past. 



BOTANY IN CALIFORNIA.— Some r;cent publications 

 on Botany issued by the University of Cilifornia are of 

 general interest. They include a beautifully iiinstrated paper 

 by Hall on ornamental trees, especially the "bottle-brush" 

 genera of the Eucalyptus order (Myrtaceae). Gardner 

 describes a new genus of Flagellafes (Leuvcnia) which is of 

 special interest in view of the importance attached to these 

 lowly organisms lying at the common base of the animal and 

 vegetable series. This new genus presents a remarkable com- 

 bination of characters which make it difficult "at present to 

 classify it, even to naming the family to which it belongs or in 

 which it has its nearest affinities." The nuclei and pigment- 

 bodies (chromatophores) are inconstant in number, while in 

 the motile phases contractile vacuoles occur at both the 

 anterior and posterior ends, while pyrenoids, gullet, and eve- 

 spot are absent. The same author also describes two new 

 genera of Green Algae which grow in association with other 

 marine algae of California. Endophyton grows inside the 

 frond of Red Algae of various kinds, and apparently forms a 

 link between the families Chroolepideae and Chaetophoreae, 

 differing from the latter in the absence of hairs. Pscudo- 

 dictyon, referred to Chroolepideae, grows among the cells of 

 the cortex in species of tangle {Laminaria). 



CHEMISTRY. 



By C. Ainsworth Mitchell, B.A. (Oxon.), F.I.C. 



ACTION OF POISONOUS ALKALOIDS ON 

 PL.ANTS. — .\i\ instructive series of experiments has been 

 carried out by Messrs. Otto and Kooper {Landw. Jalirb., 

 1910, xxxix, 397) to ascertain the effect of adding dilute 

 solutions of poisonous alkaloids to the soil in which plants are 

 grown. It was found that when a relatively small area of 

 soil was treated daily with a solution of strychnine sulphate, 

 the liquid first filtering through the soil contained the acid 

 constituent of the salt, but not the alkaloid, though this, too, 

 eventually passed through the soil unchanged. This phenom- 

 enon of temporary absorption of the alkaloid was also 

 observed in the case of perfectly sterilised soil, and was thus 

 not due to bacterial action. The presence of solutions of 

 salts of alkaloids, such as strychnine, in the soil had a pro- 

 nounced effect upon plants growing therein, checking both 

 germination and growth, and causing the fruit to be abnormal. 

 Nicotine added in the fonn of a three per cent, solution was 

 retained by the soil, apparently through the formation of 

 a loose "addition compound," for the alkaloid was not altered 

 chemically by the absorption. Eventually a portion of the 

 nicotine was decomposed and volatilised, this being apparently 

 brought about largely by the influence of heat and moisture in 

 the soil. The growth of the tobacco plant was greatly stimu- 

 lated by the addition of nicotine solution to the soil, and the 

 proportion of nicotine in the plant showed an increase. The 

 alkaloid had a similar, though less pronounced, effect upon the 

 growth of the potato, and did not appear to affect the com- 

 position of the plant. Treatment of the soil with a solution of 

 sodium nitrate had a similar stimulative action upon the 

 growth of the tobacco plant. 



THE GLA2ING OF ANCIENT GREEK VASES.— The 

 nature of the black glaze upon a Greek vase excavated at the 

 Heraeum has been examined by Mr. W. Foster ijoiirn. Aincr. 

 Chcin. Sac, 1910, xxxii, 1259), who has found that it does not 

 contain manganese, but consists of an iron compound, 

 probably ferrous silicate. The red glaze upon a Mycenian 

 vase has also been examined, the surface of the vase being 

 scraped with a diamond, and an analysis made of the resulting 

 powder. The conclusion drawn from the results is that the 

 colour of the glazing is due to the presence of a ferric 

 compound. 



