259 
Reviews of Foreign Literature. 
De la Culture artificielle des Diatomees. Dr. P. Miquel. (Le 
Diatomiste, 1892-93, pp. 93-99; 121-128; 149-156; 165-172.) 
In this series of articles just completed Dr. Miquel records, 
with great minuteness, the results of his experiments in propagat- 
ing diatoms in the laboratory. He starts out by stating that in 
order to cultivate diatoms successfully, it is necessary to provide 
them with two kinds of food—saline food and organic food. Then 
follow formule for such nutritive fluids, and directions in detail for 
using them, together with suggestions as to light, temperature and 
sterilization of the culture fluid so as to prevent the growth of 
organisms which are inimical to the growth of the diatoms. The 
experiments include marine as well as fresh water cultures, and in 
the concluding article directions are given for the construction of 
culture cells, so that the various stages of growth may be watched 
under the microscope. 
Not they least interesting portion of the paper is that which 
relates to the production of strange and abnormal varieties by 
varying the character of the culture fluid. These varieties Dr. 
Miquel calls “ teratological growths.” He states that he has fol- 
lowed them to the third generation, and describes some of the 
remarkable variations in form which resulted. 
Within the last few years much attention bas been given to the 
life history of diatoms, but no article bearing upon that subject 
has lately appeared that is likely to attract more attention than 
this. Dr. Miquel’s experiments have suggested new lines of re- 
search, and they will doubtless be reported by other diatomists. 
The results of these observations will be watched with interest. 
The experiments in regard to “ teratological growths,” in particu- 
lar, may clear up much of the present obscurity in regard to 
species, and may result in bringing together many now regarded 
as distinct. Co dick, 
Bettrage zur einer Monographie der Gattung Habenaria, Willd. 
F. Kranzlin. (Engler’s Bot. Jahrb. xvi. 52-223.) This contribu- 
tion towards a monograph of the genus Hadenaria enumerates 347 
Species, mostly South American, African and Asiatic. The only 
species noted for the United States are two Southern species, /. 
