744 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
The inflorescence differs from that of other Monotropese in being of the 
indefinite type. The pollen-grains are loose and powdery ; the pollen- 
tubes are provided with large pings, which cnt off the cavity of the 
younger from that of the older portion. The mode of development of 
the ovules agrees closely with that in Honotropa. 
£. Physiology. 
(1) Reproduction and Germination. 
Anemophilous and Cross-fertilized Flowers.* — Prof. F. Delpino 
describes the mode of pollination in the following species : — Bocconia fru- 
tescens (Papaveracese) presents an example of an originally entomophilous 
reduced to an anemophilous normal structure. Similar phenomena are 
exhibited by Dodonsea viscosa (Sapindaceae), an anemophilous member of 
a family usually entomophilous. The flowers of Erica scop aria are 
adapted for absolute and exclusive anemophily, in remarkable contrast 
to the nearly related E. arborea. In Mercurialis perennis , which is 
anemophilous and dioecious, the uppermost leaves on the female plants 
have a funnel-like form remarkably adapted for catching and retaining 
the pollen-grains. Barnadesia rosea (Compositse Labiatiflorae) presents a 
very interesting structure for promoting cross-fertilization. In Sauro- 
matum guttatum the arrangements for cross-fertilization within the 
spathe resemble those in other Araceas ; but the fertilizing insects in 
this instance are large carnivorous flies. 
Parasitic Castration.y — MM. A. Magnin and A. Giard describe the 
actions of Ustilago antherarum and other parasites on Lychnis vespertina 
and different plants belonging to the Caryophyllaceae ; they may be of 
three kinds : — androgenous , which incites the production of male organs 
in the female host ; thelygenous, which produces female organs in the 
male host ; and amphigenous, which produces the transformation in flowers 
of either sex. 
M. Giard i calls attention to the parasitic castration of Hypericum 
perforatum by Cecidornyia Hypericin and by Erysiphe Hartii. 
31. Magnin § further describes similar phenomena in Anemone 
ranunculoides attacked by JEcldium leucospermum ( Puccinia fuscaf 
resulting in more or less complete atrophy of the various floral 
whorls, especially of the carpels. 
M. Magnin | also calls attention to the androgenous castration of 
Muscari comosurn by Ustilago Vaillantii. Normally the terminal tuft of 
the spike in this species consists of perfectly neuter flowers, without a 
trace of either stamens or pistil. When attacked by the parasite, the 
flowers of this terminal tuft are deformed, but produce stamens as well 
developed and as fertile as those of the flowers in the lower part of the 
inflorescence. 
The parasitism of the aecidium of Uromyces Pisi on Euphorbia 
cyparissias produces very remarkable results. The axis is elongated and 
* Malpighia, iv. (1890) pp. 24-32 (1 pi.). 
+ Bull. Scient. France et Belgique, 1889, pp. 151-60. See Biol. Centralbl., x. 
(1890) p. 20. Cf. this Journal, ante , p. 208. 
t See t. c., p. 21. § Comptes Bendus, ex. (1S90) pp. 913-5. 
T. c., pp. 1149-52. 
