230 



KNOWLKDGi:. 



June. \9\i. 



the absence of a supply of carbon dioxide, but success has 

 only been obtained with simple freshwater Algae like 

 Spifogyra. Twenty years ago. Bokorny showed that though 

 formaldehyde is poisonous, even in ver\- dilute solutions, >et 

 a substance called oxyniethyl sodium sulphonate (easily broken 

 up into fornialdehj'de and sodium sulphitel can be used in 

 culture solutions, in the proportion of 1 per cent., without 

 injury to Spiro^yra. 



Grafe [Bcr. d. deiitsch. hot. Gcs.. 1911) has now 

 experimented with the French Bean, and finds that seedlings 

 of this plant can make use of the vapour of formaldehyde. 

 He allowed the seedlings to germinate, removed their 

 cotyledons (containing reserve food), and placed them in 

 vessels exposed to light. In some cases, the seedlings 

 were supplied with air deprived of carbon dioxide, but con- 

 taining formaldehyde vapour. 1 he results showed that the 

 plants made use of the formaldehyde vapour, producing 

 abundant sugar in their leaves, and increased greatly in dry 

 weight, as compared with the control or comparison plants 

 not supplied with formaldehyde. Apparently, however, the 

 formaldehyde prevented the formation of starch from the 

 sugar. 



A NEW FUNGUS IN THE BEET ROOT. — In the 

 course of his work on the disease of Sugar Beet caused by 

 Nematodes (round-worms), Nemec found a Fungus, belonging 

 to the Chytridiaceae, in the cortex of the lateral roots. He has 

 now {Ber. d. deutsch. hot. Ges.. 1911). given an account of 

 the structure and life history of this Fungus — a new genus 

 and species called Sorolpidiuin Bcfac. It belongs to the 

 Chytridium family, and therefore to the lowest forms of F^nngi. 

 1 1 appears in the cortex cells as a nucleated mass of protoplasm, 

 which grow s larger at the expense of the cell and finally nearly 

 fills it. Then the Fungus cell acquires a cell-wall, and its 

 contents divide into several uni-nucleate portions or sporangia. 

 Each sporangium then produces two. three, or four zoospores, 

 which escape, swim about, and infect other cells. In several 

 respects. Sorolpidimn resembles the Plasmodiophoraceae — the 

 group to which belongs the Fungus causing finger-and-toe 

 disease of the turnip. Nemec considers it as a link between 

 this group and the Chytridiaceae, and as indicating the close 

 relationship of the two groups. 



LIFE HISTORY ol' ZANARDINIA. — The genera 

 Cntleria and Ziuiardiiiia. forming the small family 

 Cutleriaceae, are of great interest, because they form a 

 transition from the lower Brown Algae, in which the sexual 

 cells, if formed, are nearly or quite alike in size, to the higher 

 Brown Algae iDictyota and Fucks series) in which the female 

 cell is an oosphere, much larger than the male cell, and 

 differing from it in not being motile. 



The life history of Cntleria has already been worked out in 

 some detail by various botanists, including Falkenberg. 

 Sauvageau and Church. The sexual and asexual plants are 

 very different, the former being an erect ribbon-like and much- 

 divided structure, while the latter is a flat creeping disc of 

 roughly circular outline. Before the connection between the 

 two forms was discovered, the asexual form was called 

 Aghjozoiiia, and was regarded as an entirely different plant. 

 Careful investigation has shown that Cntleria may be 

 regarded as consisting potentially of a basal disc, producing 

 spores, and an erect branching portion producing sexual cells. 

 The two portions require quite different conditions in order to 

 develop fully. In the Mediterranean, the Aglaozonia form 

 occurs in summer, and the Cntleria form in winter. In 

 England the reverse holds good. In the north, the Cntleria 

 form becomes more and more scarce, and the plant is repre- 

 sented by only the Aglaozonia form on the Scandinavian 

 coast. Conversely, in the south the Aglaozonia form becomes 

 rarer, and at Naples it is unknown, only the Cntleria form 

 being found there. 



The life history of Cntleria is a good illustration of the 

 influence of external conditions on the course of development 

 of the reproductive cells. Normally, the fertilised Cntleria egg 

 produces an Aglaozonia plant, but this stage may be omitted, 

 and a Cntleria plant arise directlx'. The zoiispoies produced 



by the Aglaozonia normally produce a Cntleria plant, and 

 this usually produces Aglaozonia discs from its base; the 

 Cntleria plant may undergo arrest of growth, leaving the 

 Aglaozonia to continue the life history. Northern conditions 

 favour the predominance of the asexual or Aglaozonia form, 

 while southern conditions favour that of the sexual or 

 Cntleria form. 



Vamanouchi Uiot. Magazine. Tokyo. 1911) has worked out 

 the development of Zanardinia. which is allied to Cntleria. 

 but has a disc-like thallus only. The nuclear divisions of the 

 ordinary cells of the disc-like asexual plant show forty-four 

 cliromosomes ; the division of a zoospore mother-cell shows 

 reduction, so that the zoospore has twenty-two chromosomes. 

 The zoospore produces a disc-like sexual plant with twenty- 

 two chromosomes in the nuclei of its cells ; the fertilised egg 

 cell has forty-four chromosomes, and this number is present 

 in the asexual thallus to which it gives rise. 



In Zanardinia. therefore, there is a regular alternation of 

 generations, exactly as in Dictyota. Polysiphonia and so on. 

 characterised by (1) different number of chromosomes in the 

 sexual and the asexual plants (2) one plant being asexual and the 

 other sexual. The asexual and sexual plants are exactly similar 

 in structure, apart irom the difference in the nuclei, just as is 

 the case in Dictyota and Polysiphonia. 



MAI/E SUGAR.— Doby [Cheni. Zeitnng. 1910. page 

 1330) has investigated the different forms of Maize which are 

 grown in Europe, with a \iew to their productiveness in the 

 manufacture of sugar, cellulose and alcohol. Owing to its 

 intolerance of frost, or even of cold nights. M.iize is hardly 

 grown in England, except as green fodder, its stems being 

 sweet, owing to the presence of cane sugar. Even in the warmer 

 parts of Germany the amount of sugar in Maize is not so high 

 as in .America, but the culture of Maize nevertheless pays 

 well. The largest amount of sug.ar is obtained on removing 

 the young cob before the seeds have been allowed to ripen. 

 When the cob is removed the amount of sugar passing up the 

 stem increases until it reaches a maximum, when it diminishes 

 again owing to respiration taking place in the still growing 

 stem. The stems. leaves, and even the axis of the cob. afford 

 excellent material for the manufacture of paper; the unripe 

 cobs, as well as the green stems, can be used in the manu- 

 facture of alcohol. 



THE NUCLEOPROTEINS.— A large amount of work 

 has been done in recent years, on the nucleoproteins of both 

 plants and animals. Much of this has been collected by 

 Brugsch and Schittenhelm in their text-book. "Die Nucleinstoft"- 

 wcchsel und seine Storungen " (1910). Plimmer ijonrnal 

 Chein. Soc vols. 93, 94) has indicated accurate methods for 

 the determination of the nucleoproteins according to the 

 quantity of phosphoric acid and the purin bases, which are the 

 results of the splitting of the nucleoproteins by hydrolysis. 



The nucleoproteins differ from other proteins in consisting 

 of a protein combined with nucleic acid, the latter containing 

 phosphorus, and in their resistance to the action of enzymes 

 which readily decompose the primary proteins into peptones 

 and simpler nitrogenous substances. Being essential con- 

 stituents of the nuclei of plants and animals, they play 

 an important part in the physiology of the cell, for the 

 existence and development of which they are essential. The 

 embryonic and glandular cells of animals are rich in nuclear 

 material, and contain relatively large quantities of nucleo- 

 proteins. The same is the case with the embryonic cells of 

 plants, not only in embryos, but also in the embryonic 

 tissues and growing points of the stem. It is clear 

 that formation of nucleoprotein material must take place 

 during growth of the active tissues of plants, since increase in 

 amount of nuclear material precedes the division of the 

 nucleus. 



Zaleski iBcc. d. dentscli. bot. (Jes.. 1911) has investigated, 

 by anal\sis. the changes in amoimt of nucleoproteins during 

 growth of certain plants, e.g., bean stems. lea\es, roots, onion 

 bulbs, seedlings. His results indicate that during growth 



