510 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Pollination of Nigella.* — Dr. A. Terracciano describes the floral 
structure in several species of Nigella, especially N. damascena, sativa , 
Bourgsei , foeniculacea, arvensis, and gallica , and concludes that, notwith- 
standing the conspicuous flowers, and the presence of nectaries, the flower 
is adapted for self-fertilization. 
(2) Nutrition and Growth (including- Germination, and Movements 
of Fluids). 
Germination of Araucaria Bidwilli.f — Prof. E. Heckel describes a 
mode of germination of the seeds of this species which appears to be 
quite peculiar to it. The hypocotyl swells into a large fusiform tubercle, 
which rapidly attains a length of from 4 to 5 cm., terminating in the 
root. This tubercle remains adherent to the gemmule, and the 
endosperm gives up to it its reserve food-materials, under the absorbing 
action of the green cotyledons. The ordinary mode of propagating this 
species of Araucaria is by means of the tubercles which have de- 
veloped on seeds that have already germinated. 
Dissemination of Seeds.J — Herr J. Verschaffelt states that in Salvia 
Horminum and lanceolata the seeds are set at liberty only under the 
influence of rain or moisture, the two lips of the calyx, which are closed 
when tbe air is dry, then separating. Moreover, the pedicel of the 
fruit is curved downwards when dry ; when the air is moist it straightens 
itself so that the fruits escaping from the open calyx fall at some 
distance from the plant. In Iberis urabellata the pedicels of the ripe 
fruits are pressed against one another when the air is dry, and separate 
only under the influence of moisture, or when they are softened by rain, 
thus facilitating their dispersion by the wind or by animals. This is 
not the case with I. amara. 
Period of Formation of the Flower.§ — In support of his theory that 
the substances which go to the formation of the flower are already formed 
in the green leaves, Prof. J. Sachs describes the following experiments. 
Leaves of a Begonia gathered at the end of May were propagated in the 
ordinary way on wet sand. Numerous buds were formed in the course 
of a few weeks ; but it was only after they had grown to the size of 
vigorous plants, early in November, that inflorescences were first pro- 
duced in the axils of later leaves. On the other hand, when the leaves 
were gathered from flowering plants at the end of July, and propagated 
in the same way, the buds first formed contained inflorescences which 
blossomed in October, and which were borne in the axils of the oldest 
leaves of the bud. They must therefore have been formed in the very 
youngest condition of the bud. Prof. Sachs draws from these facts the 
conclusion that the substances which are used up in the formation of the 
flowers are present in the leaves in the summer, but not in the early 
spring. 
Development of the Male Inflorescence of the Walnut.|| — Accord- 
ing to M. W. Russell, the male catkins of the walnut begin to be formed 
* Bull. Soc. Bot. I tal., i. (1892) pp. 46-50. 
f Comptes Reudus, cxiii. (1891) pp. 816-8. 
+ Bot. Jaarb., 1890, pp. 148-56; 1891, pp. 95-109 (2 pis.). See Bonnier’s Rev. 
Gen. de Botanique, iv. (1892) p. 192. § Flora, lxxv. (1892) pp. 1-3. 
[\ Rev. Gen. de Bot. (Bonnier) iv. (1892) pp. 18-21. 
