210 THE AMERICAN NATURALIST.  [VOL. XXXII. 
softens. Finally, the need of a high temperature for the combustion 
of tartaric and citric acid and the possibility of the oxidation of malic 
acid at lower temperatures explains why apples, sorbs, medlars, and 
other fruits which contain malic acid are able to ripen in cold cli- 
mates, while grapes and oranges require warmer climates. It also 
explains why fruits containing malic acid ripen in cool places after 
picking, while grapes, and especially oranges and other citrus fruits, 
do so only imperfectly. However, by raising the temperature, fruits 
containing citric and tartaric acid will ripen in the fruit house. 
E 5. 
Ferns of Nicaragua. — An attractive-looking piece of work bear- 
ing the above title forms the second paper in the Bulletin from the 
Laboratories of the State University of Towa, vol. iv, No. 2, pp. 116- 
224. The author of the paper is the well-known zoologist Mr. B. 
Shimek, who collected these plants on the island of Ometépe in 
Lake Nicaragua and in a narrow strip of country along the San Juan 
River. Over 120 species of ferns were collected in this small area 
in less than four months devoted to general botanical work. Judging 
from Mr. Shimek’s statements, the fern flora of Nicaragua appears to 
be even richer in species than that of New Zealand, but the individ- 
uals are not so numerous. Only about one-fifth of the species listed 
by Mr. Shimek occur in Fournier’s list of 121 Nicaragua ferns, and 
only about two-fifths in Mr. Helmsley’s list of 135 species. Much 
of the territory is still only very imperfectly explored. The paper 
contains some interesting general remarks on tropical ferns, a key to 
the orders and families, and a list of the species collected, includ- 
ing helpful notes and a citation of books in which descriptions may 
be found. Several species are transposed into other genera, and 
one new species is described, — Polypodium macbridense. The text 
is supplemented by twenty well-executed half-tone plates. mR Ss 
Pharmaceutical Archives.— With the beginning of the current 
year, owing to the large amount of original matter offered for the 
columns of the Pharmaceutical Review, the journal has been relieved 
of much of this matter by the starting under the same management 
of asecond journal under the heading given above. The first num- 
ber contains articles on the comparative structure of the leaves of 
Datura stramonium, Atropa belladonna, and Hyoscyamus niger, the 
popular names of Brazilian plants and their products, a chemical 
bibliography of morphine, and a study of the structure of the twigs 
