ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
391 
plumule completely emerge, but it at once proceeds to develope five- 
toothed, afterwards three-lobed leaves. In all species of Anemone the 
seeds must be sown as soon as they are ripe, and not delayed till the 
following spring. Melittis MelissopJiyllum and Dentaria pinnata and 
digitata diverge from the usual conditions of the orders to which they 
belong, in the cotyledons remaining buried beneath the surface. 
(3) In various plants the author observed the peculiarity of the apex 
of the seedling burying itself in the earth. 
(4) A fourth series of experiments related to the effect of external 
influences on the form of the leaves in seedlings, but these did not lead 
to any decisive result. 
Parasitism and Multiplication of Cynomorium.* * * § — Pursuing his ob- 
servations on the growth and mode of parasitism of Cynomorium coccineum, 
Sig. U. Martelli observes that the cone-like bodies which penetrate into 
the tissue of the host are not haustoria, but have all the characters of 
true roots. He succeeded in causing the root-like organs in a rhizome 
of the Cynomorium to penetrate the seeds of Atriplex nummularia and to 
become parasitic on that plant. The author believes that the plant has 
acquired parasitic habits in consequence of the difficulties presented in 
the way of its propagation by seed. 
Prof. G. Arcangeli f states that Cynomorium coccineum can carry 
on a parasitic existence on a number of shrubby and suffruticose, and 
even on annual plants. 
Direct Absorption of Ammoniacal Salts by Plants.! — Mr. A. B. 
Griffiths grew some bean seedlings (which had been immersed in copper 
sulphate solution to destroy nitrifying microbes, and washed with 
sterilized water), under antiseptic conditions in a sterilized solution 
containing certain ammonium salts together with others. At the end 
of four weeks the ammonia in the solution had sensibly diminished, 
and as there had been no direct atmospheric absorption of nitrogen, the 
ammonium salts must have been directly absorbed by the plant. 
Aeration of Tissues.§ — M. H. Devaux, in his resume on this subject, 
states : — (1) That the internal atmosphere of all the massive tissues 
studied contained oxygen in notable proportion ; in certain cases this 
proportion is nearly that of pure air. (2) The proportion of carbonic 
acid in the internal atmosphere is generally small. (3) The proportion 
of nitrogen is often different from that in the open air. (4) The 
internal and external pressures differ, sometimes in one direction, some- 
times in the other. (5) Tubercles and fleshy fruits may be regarded 
as being formed of a very porous mass of tissue surrounded by a less 
porous envolope (examples, apple, orange). (6) It is probable that gas 
in a free state, which has passed through the surrounding envelope, 
penetrates to the deepest tissue. (7 ) Gas either in a free or dissolved 
state can traverse the external envelope. (8) The gaseous exchanges 
produced at the surface depend on the permeability and porosity of the 
peridermal membrane. (9) Oxygen enters principally by the pores, 
* Bull. Soc. Bot. Ital., i. (1892) pp. 97-9. Cf. this Journal, ante, p. G7. 
f Tom. cit., pp. 127-9. 
j Chem. News, lxiv. p. 147. See Journ. Chem. Soc., 1892, Abstr., p. 229. 
§ Ann. Sci. Nat. (Bot.), xiv. (1891) pp. 297-395. 
