BHOET N0TE8. 213 



the particles of silica placed upon the glass slide, when they were 

 completely separated from each other, the outlines of the individual 

 diatoms were sharply and distinctly defined. On the other hand, 

 when the physical action of ebullition with nitric acid was not suffi- 

 cient for the complete separation of the particles of the epidermal 

 shield, there was observed a marvellous interlacing of the various 

 forms." The author vouches for every precaution having been 

 taken to prevent error ; but his assertion that the diatoms had 

 "entered the root capillaries," and were "conveyed by the sap-cells 

 directly to the section of the plant where they were destined to com- 

 plete its structure," is not very likely to meet with acceptance 

 amongst botanists. 



Nymph^a flava, Leitner. — The plate of Audubon's great work 

 which represents the American Swan likewise represents the flower of 

 a yellow Nymphcea, or true Water-lily, under the above name. The 

 foliage which accompanies it may be that of a JV^iiphar, but the flower 

 is that of a Nymplma. Leitner was a German botanist who explored 

 Southern Florida, and died or disappeared there — if we rightly re- 

 member, was thought to have been killed by Indians. He doubtless 

 met Audubon, and gave him the name which he published on his 

 plate. The species has properly been left unnoticed so long as the 

 whole evidence of its existence rested upon Audubon's figure of a 

 flower, accompanied as it is with Nuphar foliage. But of late years 

 we have heard of a yellow Water-lily in Florida. In 1874 Dr. Edward 

 Palmer sent us a specimen with foliage and flowers collected in Indian 

 Eiver, and certified to the yellow colour. It has now been detected by 

 Mrs. Treat on the St. John's River, and living plants communicated 

 to us, from which we may expect to see fresh blossoms. The growth 

 is very diff'erent from that of N. odorata, the rhizome being shorter, 

 and thickly beset with salient blunt tubercles ; and the plant propa- 

 gates freely by stolons. —A. Gray, in Sillimans Journal, May, 1876. 



Gardening on CnEiiiCAL Principles. — Dr. Goeppert, of Brfeslau, 

 sends the following extract from a paper entitled " Agriculture as a 

 model for Horticulture," read at a meeting of the Silesian " Gesell- 

 hait " last year. "Since the time of Liebig agriculture has been 

 managed in a rational way ; for by chemistry the chemical composition 

 of the plant to be cultivated is ascertained, and the soil is selected. 

 But nobody has ever thought of employing chemistry in gardening ; 

 there is no instance of a plant reared in gardens or houses ever having 

 been subjected to a chemical analysis, for the purpose of drawing con- 

 clusions as to the soil best suited ibr it. The practice of gardening is 

 at present no less empirical than it was two thousand years ago, in 

 spite of the constant loss of valuable plants. Nobody knows the 

 chemical composition of our tropical Orchidece, Ericacew, Australian 

 plants. Palms, &c. It is time to put a stop to this state of gardening. 

 It is necessary to analyse the earth in which the plants grow in their 

 native state, and afterwards the plant itself. Thereby we shall be 

 enabled to find out the best soil for each plant. lu this manner 

 agriculturists wei-e once, and are still, assisted by chemists : the 

 botanists must also join the chemists, in order to establish a rational 



