212 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
with a single radical long-stalked foliage-leaf ; and biennial, with two 
opposite leaves above the level of the soil. 
Root of Anemone.* — M. E. de Janczewski classifies the roots of the 
different species of Anemone under 5 groups, viz. : — (1) The primary- 
root is thick and perennial, serving as a storehouse for food-material 
{A. rivulciris, Pulsatilla ) ; (2) the primary root and the adventitious 
roots are altogether alike, and attain a medium thickness, while the 
rootlets are very slender (A. Knowltonia) ; (3) the primary root, adven- 
titious roots, and rootlets are altogether alike and are all moderately 
slender (A. sylvestris, japonica , virginiana, multifida, pennsylvanica ) ; 
(4) all the roots are very slender ( A . Hepatica, nemorosa, ranunculoides , 
trifolia, Jlaccida, baikalensis') ; (5) all the roots are filiform and fugitive, 
the only living organ during the repose of vegetation being a tuberous 
rhizome (A. appenina, coronaria, hortensis). 
Hoot of Hydro char is. | — M. G. Chauveaud has made a detailed study 
of the root of the frog’s bit, Hydrocharis morsus-ranse, and notes the 
peculiarity, not hitherto recorded in any plant, that, of the internal or 
medullary sieve-tubes which form part of the central cylinder, one 
usually occupies the axis of the root. The successive appearance of 
bundles in the central stele is a further peculiarity as contrasted with 
the simultaneous formation of the primary sieve-tubes in the roots of 
other Monocotyledons. The vascular system of the root is, in fact, 
greatly reduced, the primary vessels having disappeared, and being re- 
placed by supernumerary vessels. This is accompanied by an unusual 
development of root-hairs for the root of an aquatic plant. 
13. Physiology. 
(1) Reproduction and Embryology. 
Behaviour of the Nuclei in the Development of the Embry o-sae 
and in Impregnation.^ — Mr. D. M. Mottier gives details of further 
observations on this point, chiefly in the cases of species of Lilium and 
of Helleborus foetidus. These establish beyond doubt that neither in the 
pollen-cells nor in the rudiment of the embryo-sac are there any centro- 
spheres. In both cases the spindle-fibres are entirely of cytoplasmic 
origin. In the first process of division the lower nucleus (the one in the 
chalaza end) is larger, and its chromatin-thread is much longer and 
more coiled than the upper nucleus (the one in the micropylar end of 
the embryo-sac). The second nuclear division in the embryo-sac follows 
immediately on the first, without the daughter-nuclei having entered 
into a complete state of rest. Between the second and third nuclear 
divisions there is, on the other hand, a considerable interval. 
In the formation of the egg-apparatus, the planes in which the divi- 
sions of the two upper nuclei take place may be either parallel or some- 
what oblique, or even at right angles to one another. The cytoplasm 
which surrounds the polar nucleus is not limited by a membrane. The 
* Rev. Gen. de Bot. (Bonnier), ix. (1897) pp. 337-54 (2 pis.). 
t Tom. cit., pp. 306-12 (5 figs.). 
X Jahrb. f. wiss. Bot. (Pfeffer u. Strasburger), xxxi. (1897) pp. 125-58 (2 pis.). 
Cf. this Journal, ante, p. 91. 
