646 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Zea Mays. The bundles of the primary root are of the true radial type. 
The innermost elements of the xylem are anomalous, and it is doubtful 
whether they are true ducts. The leaf-trace bundles of the scutellum 
do not in any way affect the arrangement of the main bundles. The 
first internode closely resembles the root in structure. The fibrovascular 
bundles change from the radial type to the collateral type in the second 
node. These bundles, on entering the second node, pass outward and 
terminate blindly toward the periphery, the last elements to disappear 
being the xylem. The bundles of the sheath differ from those of normal 
leaves in that they originate in the node from which they are given off, 
that they blend into pairs, and finally, in the sheath, appear as two 
bundles at opposite points on the axis, and that the curves of this bundle 
in the node are very sharp. 
Ornithophiious Flowers.* * * § — According to Dr. J. Johow, the number 
of flowers pollinated by the agency of birds is much smaller than is 
often stated, being, in fact, nearly confined to those described as such 
by F. Muller. Humming-birds in particular, since they feed entirely 
on insects, and not on nectar, play but little part in the carriage of 
pollen. He proceeds then to describe an unquestionable ornithophiious 
species, Paya chilensis, an arborescent species of Bromeliacese growing 
on the Chilian sea-coast. The “ nectar ” is exceedingly abundant, but 
is not attractive to insects, containing only a very small amount of 
sugar in solution. It is, however, eagerly drunk by humming-birds, but 
more especially by the “ Chilian starling,” Curseus atcrrimus. In this 
way they get their heads plentifully besprinkled with pollen, which they 
then carry to other flowers. 
Cross-pollination and Self-pollination. — According to Mr. R. J. 
Webb,! the closed flowers of Gentiana Andrewsii are cross-pollinated 
by humble-bees, which forcibly open them in order to obtain the honey. 
Herr H. Ross J describes the mode of pollination in Cobsea macro - 
stemma from Guatemala, which differs in some respects from that in 
C. scandens. While normally entomophilous (through the agency of 
Sphingidm), this species shows well-developed contrivances for ensuring 
self-pollination. 
Herr E. Ule § describes the structure of the flower, and the appli- 
ances for pollination, in species of Arislolochia, natives of or cultivated 
in Brazil. In A. macroura we find one of the most perfect and striking 
examples of proterogyny known. Cross-pollination appears absolutely 
necessary for fertility, and self-pollination impossible. The flowers of 
A. elegans are almost invariably visited by a quantity of small flies of 
a particular species, which carry the pollen to the stigma. A. brasiliensis 
and cymbifera are not known to ripen their fruit. 
Dr. P. Knuth || finds Leucojum sestivum more fully adapted for cross- 
pollination by insect agency than L. vernum ; though self-pollination is 
by no means excluded. In Iris germanica the length of the nectar-tube 
(5-5J mm.), almost exactly corresponds to that of the proboscis of the 
* SB. k. Preuss. Akad. Wiss. Berlin, 1898, pp. 332-41. 
t Amer. Naturalist, xxxii. (1898) p. 265. 
t Flora, lxxxv. (1898) pp. 125-34 (1 fig.). 
§ Ber. Deutsch. Bot. Gesell., xvi. (1898) pp. 74-91 (1 pi.). 
|| Bot. Centralbl., lxxv. (1898) pp. 161-3 ; lxxvi. (1898) pp. 33-5 (2 figs.). 
