706 SUMMARY OF CURRENT RESEARCHES RELATING TO 
Tissues; Secretions. The general conclusions which lie draws, from 
innumerable coincidences between structure and environment, are that 
there is some common relationship between them of cause and effect, and 
that all parts of plants are subject to variation. While these variations, on 
the one hand, may be merely casual, accidental, and transient, they may, 
on the other hand, become more and more persistent and characteristic, 
and hence hereditary. He regards this cumulative evidence as amount- 
ing practically to a demonstration that varietal and specific characters are 
acquired solely through the direct action of the environment. The 
author concludes with some observations on the origin of the very 
general inconspicuousness and self-pollination of desert flowers. 
Adaptation of Fruits to Climate.* * * § — Dr. J. E. Jungner points out 
the adaptation in the form of many fruits to the climate, especially to 
the very heavy rainfall of the Cameroon region. This is frequently 
exhibited in a similar contrivance to that which occurs in the case of 
many leaves, a pendent habit, and an elongated apex which facilitates 
the running off of the water. Fleshy fruits are especially characteristic 
of hot climates, and — in addition to their adaptation for transport by 
animals — serve to store up moisture to counteract excessive insolation. 
Hut-like and other woody fruits are, on the other hand, more abundant 
in cold climates, where the rainfall is small during the period of vege- 
tation. 
Elimination of the Seeds of Areca Catechu. According to Herr 
Osenbrug, the rumination in the seeds of this palm makes its appear- 
ance either immediately before or immediately after fertilization. It 
commences from the funicle in the form of cushions, above the spots 
where the vascular bundles enter, projecting into the embryo-sac, ac- 
companied by branches of the bundles. The rumination, therefore, re- 
sembles that of the nutmeg in having nothing to do with the integuments. 
The structure which has been called rumination in some seeds, such as 
those of the ivy and of Hhamnus catharticus, is not properly so termed ; 
but is rather an example of seeds with folded or lobed endosperm. The 
projections which constitute the rumination, and not the interior of the 
endosperm, are the seat of the alkaloids and tannins in the Areca- seed. 
Mechanical Theory of Phyllotaxis.if — Herr A. W T eisse discusses 
the two theories with regard to the origin and persistence of the different 
modes of phyllotaxis : — that they are due to the influence of external 
conditions, and that they have become fixed in each species by heredity. 
From a series of observations made on the adventitious buds of a number 
of woody plants, he decides in favour of the former explanation. Es- 
pecial stress is laid on the fact that, in adventitious buds, the position of 
the first leaves is entirely dependent on mechanical factors. 
Double Leaves of the Honeysuckle.§ — Herr L. J. Celakovsky dis- 
cusses the cause of the occasional occurrence of four leaves in a whorl in 
Lonicera Periclymenum . It is the result of the co-operation of two 
* Bot. Centralbl., lix. (1894) pp. 65-74 (2 pis.). Cf. this Journal, 1892, p. 62. 
t ‘ Ueb. d. Entwicklung d. Samen d. Areca Catechu u. d. Bedeutung d. Rumi- 
nationen,’ Marburg, 1894. See Bot. Centralbl. lix. (1894) p. 190. 
X Jahrb. f. wiss. Bot. (Pringsheim), xxvi. (1894) pp. 236-94 (2 pis.). 
§ Tom. cit., pp. 1-48 (3 pis.). 
