^ \ 
X) r> Engelmann has lately contributed to the 
fit 
\ —— Day and Night Growth.— Dr. Engi 
Mann, in a paper on the flowering of Agave Shaw 
! records the growth in the flower-stalk of this specie 
Measurements were made by the gardener in charg 
of the plant at 7 A.M. and 7 p.m., from July 8 % 
September s, a period of sixty days. The night 
growth, from 7 p. m. to 7 a. m. was uniformly larger 
than that from 7 A M. till 7 p.m., the total growth fo’ 
the period in question being 4 6| inches, of which 
took place in the ni 8 ht and 19 i inches in 
the g. The greatest advance was made about 
the middle of the period. Temperature appeared to 
have little effect, as in the warm weather of the first 
twenty days it grew much less than in the cooler 
period which ensued in the following ten days. The 
flowers did not open tiil February 5. Dr. EngM 
Mann’s paper is published in the Transactions of til 
Academy of St. Louis, vol. iii., Nov., 1877. |Sg 
- Sensitive Stamens in Purslane.—M r 
Meehan has observed that the stamens of Poitulac 
oleracea are sensitive; when touched they rise slow’ 
and curve over the styles. 
Transactions of theAcademy of St. Louis a series of 
Agaves, especially of those natives of the 
territories of the United States, excluding, however, 
the:more numerous Mexican species. The species] 
are grouped under the heads of-i, Singuliflora?, in¬ 
cluding those which have'^but a single flower in the 
axil of each bract of th¥ flower-stalk; 2, Gemini- 
Horse* in. which there are two flowers in the axil of* 
each Bract of the flower-stalk; 3, Paniculate, 
which the flowers are arranged in dense terminal 
panicles. We may have occasion to refer to some of 
the species mentioned on another occasion. A photo¬ 
graph of Agave Shawii is given-a beautiful species, 
dedicated to. Mr.. Henry Shaw, the founder of the 
Missouri Botanic Gardens. In compliance with 
general usage, it would have been better to have 
called this A. Shawiana, for it does not appear that] 
Mr. Shaw had anything to do with the discovery on 
description of the species. Dr. Engelmann wishes 
to direct the attention of observers to the following 
points, which we reprint in the hope that those who 
have the opportunity may be able to give the required 
information :— 
I wish to direct the attention of botanists who have 
t opportunity to observe the development of these 
plants to the following questions At what hour of the 
day do the anthers of the different species burst and 
begin to shed their pollen? When do they become 
entirely effete, and in what state is then the style? How 
long aftefwards, and when does the style of the same 
flower attain its full development, and when and how 
much do the stigmatic lobes open or spread, and when 
does the stigmatic liquid fill the cavity of the style and 
cover the inside of the lobes ? I have above given an 
account of these physiological processes in A. virginica , 
the only reference to them in literature which I can find 
is made by Jacobi, Ag . 310, where he says of an Agave 
of the second section that the full development of the 
style and the separation and partial spreading of its 
lolaes takes place'' only after the stamens have faded 
gpes, fully coincides with my observa¬ 
tions* His further remark, that the stamens are not 
ipflexed in the buds of that species (A. Goeppertiana), is 
Unquestionably erroneous. Of the floral development 
6i the Agaves of the third section, nothing at all seems 
to be known. I wish also to direct the attention of 
Observers to the time and nature of the secretion of 
Iqtiey in the lower part of the flower-tube. The inflo- 
of those Agaves of the second section which are 
id to bear one or three or six to eight flowers in a D * 
fascicle requires further investigation." 
1. Notes on Agave; by Geo. Engelmann;, M.D.—This is a 
modest title of a paper in the TraDsacffiSi*bf the Academy of 
Science of St. Louis, Missouri, vol. iii, December, 1875. Sepa¬ 
rately issued it forms a pamphlet of 35 pages, 8vo. If we mis¬ 
take not it begins that volume; so that the pages of the pamphlet 
ton for “4 Trenton.” 
9, 9, /or “8,” “8,” 
P. 419, 4 1. fr. foot, 
r two for “three or 
jbeen changed so as 
iota and the eastern 
tation is not, with 
P. 675, 15 1. and 
I. 699, 16 1. fr. foot, 
^transverse to the 
h substituted:—an 
had been subjected 
1 To the first para- 
j* by Prof. Verrill] 
ntic would give the 
higher temperature 
id, therefore; of an 
ns along the cold 
ftheory adopted for 
k the cold and the 
Cretaceous column. 
23456 7 89 10 Missouri 
Botanical 
copyright reserved garden 
