SCIENTIFIC SUMMARY. 
319 
rahman al-Sufi, in the tenth century, who evidently observed their magni- 
tudes with minute exactness; so that his labours are unrivalled even to 
the epoch of Argelander’s “ Uranometria Nova.” Dr. Schjellerup has 
given a very interesting comparative table of the magnitudes of the prin- 
cipal stars, from Ptolemy, Sufi, and Argelander, which shows that on the 
whole they are as accordant as could be expected. — Observations of the 
nebulae, and measurements of the positions and distances of neighbouring 
nebulae and stars, have been continued at Parsonstown. — The original tele- 
scopes of Galileo have been sent over from the Florentine Museum to our 
Scientific Loan Exhibition. — Colonel Cooper’s Observatory at Markree, con- 
taining the great 13-3-in. Cauchoix achromatic, which has been long suffer- 
ing greatly from neglect and decay, is now being restored as far as possible 
under the care of Dr. Doberck, and good work may be expected from it. 
BOTANY AND VEGETABLE PHYSIOLOGY. 
The Growth of the Male and Female Flowers of Valisneria Spiralis. — In 
reference to a note on this subject in our number for April, Mr.W. Morrison, 
the Honorary Secretary of the Dundee Naturalists’ Society, sends us the 
results of some experiments that were conducted by Mr. J. Hood, one of 
the Vice-Presidents of that Society. He says : u The plants have been in 
cultivation since 186*5, and during that time there have been female flowers 
four seasons and male flowers on two seasons ; the latter in the years 1869 
and 1875. The plants continued in flower from June to about the middle 
of August. The male flowers, including peduncle, never exceeded 1* 
inches in length, and the length of the portions above the soil ranged from 
f to 1 inch. From their shortness they may sometimes escape observation. 
The results of the observations on the rapidity of growth in female flowers 
were : — 
1875 
June 30 8 p.m. 
July 1 9 - 30 a.m. 
„ „ 8 P.M. 
„ 2 9-30 a.m. 
measured plant, and found it to be 
2 inches in length 
increase 11* inches in 13* hours 
V ^8 V 1) ^2 )t 
)) 11 V } t 13 * „ 
31* 37* 
The observations were not continued further. It will be seen that the 
flower increased in length 29* inches in 37* hours, and that the increase 
was much more rapid by night than during the day. Seedling plants are 
growing in the aquarium from last year’s seed.” 
Experiments on the Digestive Power of Plants. — It is stated by a contem- 
porary that Dr. M. T. Masters has been experimenting on the functions of 
the nectaries formed by the small cup-shaped petals of Hellehorus , and finds 
that they absorb or digest nitrogenous substances, repeating in all respects 
the phenomena of the leaves of Drosera and Dioncea. 
