322 The Botanical Gazette. [August, 
Cunila Mariana [Darlington, 1837; John Le Conte, 1850; L. F. Ward, 1893; 
MacDougal, 1893; Atkinson, 1885-6. (see Bor. Gaz. 19: 40-42. 1894.)] 
Pulchea camphorata DC. [John Le Conte, 1850. ] 
Helianthemum Canadense [Eaton and Bigelow; publ. 1837 by Darlington. 
Lantana aculeata, Tagetes Bonariensis, Perilla arguta, Alonsoa incisifolia, 
Cuphea cordata, C. tubiflora, C. platycentra, Manulea oppositifolia, Calce 
laria perfoliata [Bouché and Caspary, 1854. 
Viburnum Tinus [Hoffmann, 1857.] (?) Vernonia sp. [Atkinson, 1885-6,] 
Aucuba sp. [Hoffmann, 1857]. : 
Gymnocladus sp., Ailanthus. sp., Juglans sp., Asimina triloba, Paulownia, 
leaves. [von Mohl, 1860. 
Rhamnus sp., Amygdalus communis [Bay and Jensen, in scheda, 1887-8] 
The splitting of wood and the appearance of ice-crystalsin 
the fissures are well known phenomena to tree-planters. In 
twenty-seven plants, the crystals have been hitherto observed; 
only those who do not possess sufficient knowledge of the 
literature will believe that a re-discovery has been made. : 
The occurrence of similar ice-crystals on the ground is we! | 
known in Germany where the crystals are called ‘Se 
(comb-ice); it has been investigated by J. Le Conte, von Mohi, 
Sachs, Hoffmann, and Caspary. meee 
The many observations on sections of plants, os - 
Sachs, Niigeli, H. de Vries (Botan. Zeitung 37: 649. pe 
and by H. Miiller-Thurgau (Landw. Jahrb. 9:) shou ee j 
mentioned in this connection, only because they afford gh 
portunity of forming an opinion of the causes of these 
nomena. * 
b. Forms of the crystals. 
1. Single ice-columns on the surface [E ee 
Sachs, Bouché and Caspary]; id. on the surface of pe ; A 
gh of Beta [Sachs; see also Bonnet, Usage des eh 
XXXII. 1754. ana, 
a fede united in sheet crystals [Herschel ey 
Le Conte, Bouché and Caspary, Ward, MacDougal, bay *" | 
Jensen]. : euttitt 
3. Crystals of ice united and forming a layer on th 
(a) under the bark of dead trunks, [Herschel], @) pulvinus 
trunks [Caspary], (c) on the fresh surface of the le fi ‘sections 
of falling leaves [von Mohl], (d) on the surface Of °" 
[Sachs, Niageli, de Vries, Miiller-Thurgau.] and two (- 
In consequence of this, MacDougal’s results oné ined, 
C., p. 351) are premature, and cannot b enaese 
they do not represent all of the observatio Bor ou 
4On i in winter see Russell, POT 5 183 
pib-ze2, 189, and J Le’ Conte, Am Jour SoH 1: 89% 95 
lliott, Hoffman? 
