APRIL, 1900. GRAENICHER— FERTILIZATION OF FLOWERS, ETC. 
75 
belliferae (Parsley family) had been regarded as a family pro- 
ducing without exception species with protcrandrous flowers, 
flowers emptying their supply of pollen before the corresponding- 
stigmas become receptive. 
In 1888, Chas. Robertson (2) published a paper on "Pro- 
terogynous l^mliellifcrae/' in which he confirmed Focrstc's views 
on Erigcuia bulbosa and added the four following species of this 
country to the list of proterogynous Umbelliferae : Scniicitla 
marylandica, L., Zizia aurca, Koch., Piinpinclla iiitcgcvrima, 
Benth. & Hook, and Polytaenia Nuttallii, D. C. In 1891, Kirchncr 
(3) discovered in the vicinity of Venice, in Italy, a proterogynous 
species ( Echinophoni spinosa, L.) among the European I'm- 
belliferae. From all this it is evident that to Erigciiia biilbosa be- 
longs the distinction of being the first umbelliferous plant in 
which proterogyny was recognized and reported. 
In the locality where my observations have 1)cen made, the 
plants of Erigciiia bulbosa rise 12 to 18 cm. above the ground and 
grow together in small patches. In the first or female stage, the 
two styles bearing the receptive stigmas at their summit protrude 
from the little white, purplish-tinged flower, but none of the 
anthers are shedding pollen. The five erect petals enclose the 
stamens, and the latter are incurved in such a manner as to partly 
conceal the nectar-glands from view and afford them protection. 
Nectar is secreted in al^undance on the greenish disc on top of 
the ovary. Later on the petals and also the styles become diver- 
gent, the stamens assume an erect position, and one by one the 
anthers burst open and expose their pollen ; in this way the flower 
enters into the second or male stage. 
Pollination takes place in the female stage, w^hen an insect, 
arriving from another flower in the more advanced male stage, 
and having grains of pollen attached to dififerent parts of its body, 
comes in contact with the receptive stigmas. In lirigciiia bulbosa 
Ave have a well marked case of proterogyny, the stigmas l^eing 
receptive long before the anthers of the same flower dehisce, and 
such a contrivance generally results in securing cross-fertilization, 
and, on the other hand, in preventing self-fertilization. 
Although the flowers of our first representative of the Um- 
belliferae appear so early in spring that very few insects might be 
expected to render their services as cross-fertilizers, yet observa- 
tion shows that even in our surroundings, with prevailing cool 
weather at that time of the year, the flowers are visited sufficiently 
to obtain favorable results. Under adverse circumstances, the in- 
(2) C. Robertson. Proterogynous Umbelliferae. Bot Gazette. Vol. XIII (1888) p. 193. 
^'^ Blueten der Umbelliferen. Jahresh. d. Ver. f. Vaterland. Naturk. in 
Wuerttemberg:, 1892, pp. 89-91. 
