Febbuaky 15, 1907] 



SCIENCE 



261 



(and the impression has grown since) with 

 the insecurity of diagnoses of wild hybrids. 

 Inferential evidence must be accepted that 

 the plant is a hybrid in the first place and 

 in the second place the parentage must to 

 a considerable extent be assumed. 



The ease which came under our observa- 

 tion was perhaps clearer than some others 

 because one of the supposed parents, Salix 

 Candida, was confined to this particular 

 locality. No other station is known for 

 the plant within a radius of forty miles. 

 The other parent might have been any one 

 of several willows growing near by. The 

 morphological characters of the hybrid 

 pointed strongly toward S. cordata as the 

 other parent, and it was so decided in the 

 published paper. 



After the publication we undertook to 

 hybridize artificially S. cordata and S. 

 Candida, with the result that duplicates of 

 our wild hybrids were produced. It be- 

 came at once interesting to inquire into the 

 conditions under which the wild hybrids 

 were produced. As stated above, one of 

 the parents was local. The area covered 

 by the bog is less than an acre. It is com- 

 pletely surrounded with hard ground that 

 was covered in its primeval condition with 

 a heavy growth of trees. After the coun- 

 try was cleared up the owner of this swamp 

 (before 1870) made an attempt to convert 

 it into agricultural land by drainage and 

 tillage, and succeeded to the extent of low- 

 ering the water level so that he could clean 

 the surface and in a dry season plow it. The 

 ground proved to be full of copious springs, 

 and in spite of the complete system of 

 ditching, it remained too wet to be manage- 

 able. During the period of cultivation 

 Salix Candida was nearly exterminated. 

 It, however, maintained itself sparsely 

 along the ditches. When the farmer aban- 

 doned his attempt at reclamation Salix 

 cordata, which grew in abundance in the 

 vicinity, invaded the swamp. A fertile 



and unoccupied seed-bed was afforded, and 

 plants that found it congenial took posses- 

 sion. Of the shrubs, Salix Candida and its 

 hybrids apparently succeeded best, and the 

 result is a plantation of very interesting 

 willows, a complete series of which have 

 been taken. It seems highly improbable 

 that these forms appeared in the swamp 

 prior to 1880, as Professor Dudley and 

 other students had studied the flora of this 

 particular place carefully and repeatedly. 

 The conditions existing in this peat bog 

 have suggested to the writer that the clear- 

 ing of the country may have given similar 

 opportunities to other species. The nu- 

 merous forms of Cratcegus and other types 

 recently described, readily adapting them- 

 selves to open conditions, may have had 

 their rise under conditions similar to those 

 in which our hybrids of Salix Candida de- 

 veloped. 



A Natural System of the Discomycetes : F. 

 E. Clements, University of Nebraska. 



Spore Forms of Spegazzinia ornata Sac- 

 cardo: Eenst A. Bessey, Subtropical 

 Laboratory, Miami, Florida. 

 Two spore forms are known for this 

 fungus, one long-stalked with spiny proc- 

 esses and one short-stalked and smooth. 

 According to Saccardo the latter are borne 

 on the spines of the former. Cultures have 

 demonstrated that the forms are independ- 

 ent of one another and arise directly from 

 the fungus mycelium. 



Accelerated Blossoming due to Defoliation 



by Storm: Ernst A. Bessey. 



On October 18, Miami, Florida, was 

 visited by a hurricane of great intensity, 

 lasting about nine hours. The wind at-' 

 tained a velocity of probably seventy-five 

 to eighty miles an hour and possibly still 

 higher for certain gusts. To a consider- 

 able extent both native and exotic trees 



