141 
Self-Fertilization, 418; Gard. Chron., Jan., 1880, 81 ; July, 1880, 
110. Other references occur in the additional papers to which I 
have already referred, as well as in many of these. 
EXPLANATION OF FIGURES. 
1. Longitudinal section of the ovary of Yucca filamentosa, 
on the line A—B of the next figure, x2. 2 
‘2. Cross section of the same, at about the middle, x6. 
3. A portion of 2, at G,x200. 
G, the nectar gland, opening at D into g, the conducting 
groove into which its secretion is poured and in which it passes 
to N, where it appears at the outside of the ovary. 
_ Since the foregoing was written I have had an opportunity 
‘to observe Y. angustifolia in full bloom in the Ute Pass, north 
of Manitou, Col. The nectar glands of this species are about as 
in Y. flamentosa, and open and discharge their secretion similarly, 
but I have found the latter rather more abundant. The stigma 
of Y. angustifolia is rather larger, and very green, as contrasted 
with the white stigma of Y. filamentosa, and its secretion is more 
abundant, so that frequently a prominent drop is visible between 
its lobes. The pistil differs in that the stigmatic cavity is short 
aud does not communicate with the ovarian cells, so far as can 
be seen with a three-fourth lens. 
One or more species of Pronuba and Prodorus are met with in 
the flowers in considerable numbers. The opportunity has not 
offered for watching the former at night; but many of the flowers 
are pollinated, the abundant white pollen contrasting so strongly 
with the dark green stigma as to render its presence evident even 
to the naked eye. Scattering dried capsules on the stalks of. last 
year and an abundant crop of this year’s fruit attest the efficacy 
_of this pollination, which could only have been effected by the 
moths in the flowers I refer to. 
JULY 19, 1886. 
Some Californian Polypetale. 
By. E. L. GREENE.. eos 
STREPTANTHUS NIGER.—1 to 3 feet high, paniculately 
branching from near the base, glabrous and glaucous; leaves 
linear, 2 to 3 inches long, the lowest with narrow, divaricate, 
