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SCIENCE. 



[N. S. Vol. IX. No. 214. 



Influence of Inversions of Temperature and 

 Vertical Currents of Air upon the Distribution 

 of Plants: Peofessoe D. T. MacDougal, 

 University of Minnesota. — As a result of 

 observations made at Flagstaff, Arizona, 

 the author concludes that inversions of 

 temperature through diurnal changes and 

 resultant air currents are more important 

 in affecting plant distribution than has 

 hitherto been supposed. Such changes 

 tend to give minor highlands a more equa- 

 ble temperature than adjoining hills and 

 canons; to deflect zonal boundaries on great 

 level plains and among minor topographical 

 features, and to favor the growth of mois- 

 ture-loving species along the margins of 

 table-lands bordering on valleys. 



Peculiarities of the Distribution of Marine 

 AlgcB in North America: Presidential Ad- 

 dress, De. W. G. Faelow, Harvard Uni- 

 versity. — This address, illustrated by maps, 

 discussed the distribution of North American 

 Marine Algse with particular reference to 

 the factors, temperature, direction of ocean 

 currents, character of coasts, etc., deter- 

 mining it. It is expected that it will later 

 foe published in full. 



Some Appliances for the Elementary Study of 

 Plant Physiology : De. W. F. Ganong, Smith 

 College. — The author exhibited and de- 

 scribed some simple and inexpensive ap- 

 pliances invented by him for illustrating 

 some of the more fundamental physiological 

 facts and phenomena of plants. These in- 

 cluded a temperature stage,a clinostat, a self- 

 recording auxanometer, an osmometer, a 

 way of demonstrating the exchange of gases 

 in respiration, a germination box, a useful 

 way of preparing plants for transpiration 

 weighings, and au efficient way of gradua- 

 ting growing roots, etc. 



Some Notes on the Repiroduction and Develop- 

 ment of Nereocystk : Peofessoe Conway 

 MacMillan, University of Minnesota. — 

 The author described his observations upon 

 the life-history of this species, giving par- 



ticular attention to the ecological aspects 

 of the subject. 



The Formation and Structure of the Dissepi- 

 ment in Porothelium: De. E. A. Buet, Mid- 

 dlebury College.^ — -The author traced the 

 development of the fructifications oi Porothe- 

 lium fimbriatxmi from their origin to the tube 

 stage, and contrasted the structure of the 

 dissepiment in different cases. 



Gelatin Cidture Media : De. Eewin F. 

 Smith, Department of Agriculture. — The 

 author spoke of the value of gelatin cul- 

 ture-media and pointed out certain precau- 

 tions to be observed in its use, particularly 

 with reference to the fixing of the melting- 

 point, the occurrence in it of sugar and of 

 acid salts, and how the influence of these 

 may be overcome. 



Notes on the Relative Infrequence of Fungi 

 upon the Trans-Missouri Plains and the Adja- 

 cent Foothills of the Rocky Mountain Region : 

 Dr. Chaeles E. Bessey, University of 

 Nebraska. — An abstract of this paper, given 

 by Dr. Erwin F. Smith, showed that the 

 author had noted, in the course of his four- 

 teen years' collecting of fungi in the region 

 named, that the number of species of fungi 

 is large while the number of individuals is 

 small, exactly the opposite of what is true 

 in the same region for the flowering plants. 



Different Types of Plant Diseases Due to a 

 Common Rhizoctonia : Messes. B. M. Duggae, 

 Cornell University, and F. C. Stewaet, 

 New York Experiment Station. — The stud- 

 ies of the authors have shown that a stem 

 rot of the carnation is due to a fungus 

 agreeing precisely with Rhizoctonia Betce, 

 which has caused a serious rot of sugar 

 beets in New York during the past year. 

 The fungus is described and suggestions 

 given for its treatment. 



The Stem Rot Diseases of the Carnation : Me. 

 F. C. Stewaet, New York Experiment 

 Station. — The author points out that two 

 distinct diseases of carnations have been 

 confused. One is that described by him- 



