H. BOTANY. 3 63 



source of ammonia, by further distillation. 6 C, September 

 11,1873,368. 



NEW SPECIES OF PLANT FORMING A CARBONATE OF LIME 



INCRUSTATION. 



Wibel and Zach arias have observed in the River Bille, near 

 Hamburg, large quantities of a species of Potamogeton, which, 

 like many conferva?, algge, etc., accumulates an incrustation 

 of beautiful crystalline carbonate of lime. The process is 

 due, it is suggested, to the removal of one equivalent of car- 

 bonic acid from the bicarbonate in solution. 28 C, 3Iag, 

 1874,393. 



ORNAMENTAL BEGONIAS. 



Dr. Sacc, in Les Mondes, calls attention to a new form of 

 ornamental begonias, suited for window plants, which differ 

 from those first introduced in the fact that, while the leaves 

 are small and highly ornamental, the flowers are large and 

 brilliant. In one of these, which he calls Begonia siderie, the 

 stems are red and the leaves dark green, thick, and smooth, 

 while the flowers are of a most beautiful red. One of these 

 begonias, received by him in May last, had four leaves, and 

 was barely an inch high. In June it put forth its first flow- 

 ers, with which it was constantly covered for many months, 

 forming ultimately an enormous tuft sixteen inches in diam- 

 eter and as many in height. No plant known to Dr. Sacc 

 flowers so freely, and is so easily cultivated; and he is con- 

 vinced that, in a few years, as ornamental window plants, the 

 flowering begonias will dethrone all others. 3 jB, November 

 27 1873,570. 



RECENT PUBLICATIONS IN SYSTEMATIC BOTANY. 



Among the recent publications in systematic botany should 

 be mentioned the long-delayed report by Dr. Torre y upon 

 the collection made in California and the Columbia Valley 

 by the Wilkes exploring expedition. This was prepared long 

 ago, and a set of superior steel engravings designed to ac- 

 company it were printed and partially distributed. The text 

 is now added, under the care of Dr. Gray, but with few changes 

 in the original matter. Though much that was new is no 

 longer so, the report will be of value as giving the latest 



