62 SUMMARY OF CURRENT RESEARCHES RELATING TO 
Dispersion of Seeds in Excrement."^— Herr E. Huth gives a list of 
100 flowering plants, the seeds of which are disseminated through the 
agency of birds and other animals. In the Tropics monkeys and bats 
play an important part in this respect. 
(2) Nutrition and Growth, (including- Movements of Fluids). 
Importance of Potassium for the Growth of Plants.! — Herr E. 
Liibke finds, from experiments on Phaseolus multiflorus, that, when 
supplied with only a very small amount of potassium-salts, assimilation 
and metastasis still go on, although the vegetative processes are greatly 
reduced in energy. P. vulgaris, grown in a nutrient solution containing 
no potassium, showed much greater vigour than when grown in pure 
water, metastasis, cell-division, and the growth of the organs still pro- 
ceeding. Even the formation of reproductive organs takes place, and 
the seeds, though small, are capable of germination. The energy of 
growth of Polygonum Fagopyrum exhibited, under similar circumstances, 
much greater deterioration. The author concludes that potassium is 
not absolutely essential for any one function of the plant ; but that it 
plays in the vital processes a part similar to other elements, such as 
nitrogen, phosphorus, or sulphur. 
Multiplication of Bryophyllum.t— Mr. B. W. Barton describes the 
mode of production of buds on the margins of the leaves of Bryo- 
pliyllum calycinum. A growing point is first formed from a group of 
embryo-cells situated at the base of the notches of the crenate leaves ; 
and the first sign of activity of the new bud is the protrusion of usually 
two roots. The plantlet arising from the bud attains considerable size 
while still attached to the parent-leaf, which appears to carry on the 
work of assimilation for the benefit of the offspring. 
Power of Transplantation of Organs.§ — Herr H. Vochting has 
conducted a series of experiments for the purpose of determining whether 
a part of a plant will continue to grow when planted on another organ of 
the same kind. He finds that this is almost always the case, and even 
when planted on an organ of a different kind. From this he draws the 
conclusion that every part of the stem and of the root is polarized like 
the parts of a magnet ; aud that every living cell of the root and of the 
stem has an upper and lower, an anterior and posterior, and a right and 
left half ; the latter being apparently constructed symmetrically. 
Climbing Shrubs. |] — Herr H. Schenck describes the mode of 
climbing of a number of Brazilian Hanes belonging to the orders 
Polygalaceae, Leguminosae, Hippocrateaceas, and others, which he calls 
“ twig-climbers.” The climbing is effected by the young leafy lateral 
branches being sensitive on the side in contact with the support. These 
then twine several times, continue to grow and increase in thickness, 
* Samml. Naturw. Vortrage (Berlin), iii. (1889) 35 pp. ; and Hutli’s Monatl. 
Mitteil., vii. (1889) 21 pp. See Biol. Centralbl., ix. (i889) p. 263. 
t Landwirtli. Jahrb., xvii., pp. 887-913 (1 pi.). See Bot. Centralbl., xxxix. 
(1889) p. 351. X Johns-Hopkins Univ. Circ., viii. (1889) pp. 38-9. 
§ Nachricht. K. Gesell. Wiss. Gottingen, 1889, pp. 389-403. See Bot. Centralbl 
xl. (1889) p. 112. 
11 Yerhandl. Naturw. Ver. Preuss. Eheinb, xlvi. 1889 (S.B.), pp. 9-10. 
