264 



SCIENCE 



[N. S. Vol. XXXIII. No. 842 



from Devil's Lake but are present in great quan- 

 tities. Detailed physical and chemical experi- 

 ments await further investigations, but present 

 information does not indicate that the toxic 

 action of salts is responsible for the Devil's Lake 

 inhibition of plant forms growing in bodies of 

 sweet water adjacent to Devil's Lake. 

 Nuclear Phenomena in the Basidium and in the 



Germinating Spores of Dacrymyoes and Tre- 



mella: E. M. Gilbeet. 



The discovery of the fusion of two nuclei in the 

 basidium and the further fact that the cells from 

 which the basidia arise are binucleate, has made 

 it of vital interest to discover the origin of this 

 binucleate condition. The writer finds that the 

 spores of certain species of Dacrymyoes and 

 Exidia are uninucleate and become in germina- 

 tion, successively two, four and eight celled, each 

 cell being uninucleate. Germ tubes are then 

 developed and a mycelium formed, the cells of 

 which have a single nucleus. The binucleate con- 

 dition does not then arise at the germination of 

 the spore or in the young mycelium. Dangeard, 

 Perrot and Maire find that the subhymenial cells 

 of various forms are binucleate. The writer finds 

 a nuclear fusion in the young basidia of Exidia 

 albida and Dacrymyoes sp. The double division 

 of the fusion nucleus in species of Exidia and 

 Tremella studied, suggests, in many of its fea- 

 tures, that chromosome reduction occurs at this 

 stage. Synapsis and diakinesis are well marked 

 stages. The two spored basidia of Daerymyees 

 as noted by Juel and Dangeard raise an interest- 

 ing question as to the method of reduction in this 

 form. 

 The Organization of the Chromosomes in Garex: 



A. B. Stout. 



The visible structures in the resting nuclei in 

 the root tip of Carex aquatilis and their behavior 

 throughout mitosis make it plain that here the 

 chromosomes are permanent individuals which 

 can be identified not only in resting nuclei, but 

 throughout the entire process of nuclear and cell 

 division, except for a short time during the 

 diaster stage when they are closely massed to- 



The chromosomes are also arranged in a defi- 

 nite serial place relationship which is preserved 

 throughout the late prophases and the equatorial 

 plate stage. There is thus maintained through- 

 out all stages of division a definite relative posi- 

 tion of the chromosomes. 



The spheroidal shape of the chromosomes is 

 quite constant and uniform. There is, however, 



marked growth in their volume during early pro- 

 phases until they reach their maximum size, 

 which varies from 0.3 ii to 0.4 /i. in diameter. 

 This rather constant spheroidal shape facilitates 

 the identification of the individual chromosomes 

 throughout the various stages. At one stage in 

 the late prophases the chain of chromosomes is 

 tightly coiled about the nucleole. 



This behavior of the chromosomes in Carex 

 gives positive evidence in support of the view 

 that chromosomes are permanent individuals with 

 a definite and permanent relative arrangement in 

 the nucleus. 



The following papers were read by title: 



TJie Relation of Aspergillus niger, Penioillium 

 digitatum and other Orgamsms to Tannic Add 

 Fermentation: Lewis Knudson. 



Some Problems in the Breeding of Sugar Beets: 



C. O. TOWKSEND. 



The Oxygen Minimum, and the Germination of 

 Xanthium Seeds: Chabi.es Albeet Shull. 



Evaporation Studies in the Sand Dune Plant- 

 associations of Lake Michigan and in the Beech 

 Forest: George D. Fuli.eb. 



Studies of Castilla Seedlings: Pehe Olsson- 

 Seffee. 



Some Experiments on the Colors of the California 

 Poppy: Pehe Olsson-Sefeee. 



Some Physiological Conditions in the Culture of 

 Spirogyra: W. D. Hoyt. 



On the Character of the Besin-tissue of the 

 Araucarvna^ and the Podocarpinew : R. B. 

 Thomson. 



The Anthendia of the Lahoulbeniacece : J. H. 

 Faull. 



Homothallic Conjugation in Rhizopus: Floeence 



A. McCOEMICK. 



Henet C. Cowles 

 The Univeesitt of Chicago 



TEE AMERICAN SOCIETY OF ZOOLOGISTS 

 CENTRAL BRANCH 



The annual meeting of the American Society of 

 Zoologists, Central Branch, was held in conjunc- 

 tion with Section F of the American Association 

 for the Advancement of Science in Pillsbury Hall 

 of the University of Minnesota, Minneapolis, 

 Minn., on December 28, 29 and 30, 1910, Professor 

 C. E. McClung, of the University of Kansas, pre- 

 siding. 



The committee on nomenclature appointed at 

 the Iowa City meeting reported that it was 

 making progress in the formulation of a plan 



