JUNE 7, 1901.] 
rable geometer, and a minute analysis of 
his works; perhaps might be added some 
brief articles by very illustrious living 
mathematicians; something, in fine, which 
would be as a funeral crown offered to the 
memory of the great dead. 
[Written by Juan J. Duran-Loriga for 
Le Matematiche, and translated by the Eng- 
lish editor G. B. Halsted. ] 
THE EXTRA-NUPTIAL NECTARIES IN THE 
COMMON BRAKE, PTERIDIUM 
AQUILINUM. 
THE common brake, Pteridium aquilinum 
Kuhn (Pleris aquilina L.) has for a num- 
ber of years been used in educational insti- 
tutions in this country as a laboratory 
type, more especially in connection with 
introductory courses in general biology in 
which both animal and plant types are 
used. That the presence of nectar-secret- 
ing organs in this form, therefore, should 
have been so generally overlooked as the 
writer has been led to believe, the more es- 
pecially as they were made known to the 
botanical world as early as 1877,* is a 
matter of some surprise. 
It is our purpose by means of the present 
paper to review the facts already published, 
and to present them, together with the 
writer’s own observations, in order to draw 
to the attention of teachers of biology the 
fact of the presence, in a non-flowering 
plant, of an organ such as is thought of 
usually in connection with the phaner- 
ogams alone. Interest attaches to this 
structure, also, from the fact that a definite 
organ of secretion may be observed by 
students in a much-used laboratory type, 
thereby enhancing its value as such. 
The extra-nuptial nectaries in Pteridiwm 
aquilinum were discovered by Francis Dar- 
win (l.c.), and their microscopic ap- 
pearance was briefly described by him in 
* Darwin, Francis. Jour. Linn. Soc. 15: 407. 
1877. 
SCIENCE. 
885 
1877. The possible biological meaning of 
these organs was also discussed. 
Two years later, Bonnier* pointed out 
the presence of similar structures in certain 
genera of ferns, namely, in Cyathea, in 
Hemitelia and in Angiopteris, and briefly 
described some points in their anatomy. 
In addition, this author examined the 
nectar of the plant here under discussion. 
In 1891, in view of the scanty description 
till then extant, W. Figdory published a 
fuller account of the neetaries in Pteridiwm. | 
This description includes the external ap- 
pearance and the histology of the gland, 
and is accompanied by two illustrations. 
Later in the same year Figdor’s paper was 
reprinted, accompanied by some notes 
and one illustration} additional, by H. 
Potonié. § 
EXTERNAL APPEARANCE, 
The nectaries in Pteridiwm aquilinum oc- 
cur on the fronds at the bases of the pinne 
and pinnulee on the morphological lower 
side of theleaf. The largest and most con- 
spicuous are the lowermost, that is, those at 
the bases of the first pair of pinne. On one 
developing frond,therefore, one may observe 
a complete developinental series. When 
examined macroscopically the glandsappear 
as approximately oval areas just below and 
extending somewhat into the angles formed 
by the mid-veins of the first and second, 
and second and third, orders. The exter- 
nal surfaces of the glands are smooth, be- 
cause of the absence of the chaffy scales 
found elsewhere on the young frond. 
* Bonnier, G. ‘ Les nectaires.’ Ann. Sci. Nat. Bot. 
VI. 8: 5-212. 1878: 
{ Figdor, W. ‘ Ueber die extranuptialen Nectarien 
von Pleridium aquilinum.’ Oecesterr. botan. Zeitschr. 
No. 9: 18911" 
{ Reproduced in Engler and Prantl’s ‘ Natiirlichen 
Pflanzenfamilien,’ 14: 67. 
2 Potonié, H. ‘Die ‘ extranuptialen’ Nectarien 
beim Adlerfarn.’ Natur-Wiss. Wochenschr. 6: 401. 
4 O. 1891. 
