ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
321 
to near the surface of the ground several feet from the mother-plant. 
Here they produce adventitious buds, and a number of young plants 
may originate from a single propagating root. 
Structure of Conopholis americana.* — Dr. Lucy L. W. Wilson has 
made an exhaustive study of this parasite, belonging to the Orobancheae, 
found only on the' 1 oak. The extreme degradation of the parasite, and 
the intimate relation between it and the root of the host, are comparable 
rather to the parasitism of the Balanophoraceae and Rafflesiaceae than to 
that of the parasitic Scrophulariaceae. The seedling parasite grows 
steadily for 10 or 12 years after it attacks the oak-root, until a huge 
mass 6 in. in diameter is formed. This mass is characterised chiefly 
by the abundance of sclerenchyme patches, developed by the host through 
the irritant action of the parasite. Stomates occur on the stem but not 
on the scale-leaves. The double circle of bundles traversing the flower- 
ing stem is peculiar in their xylem-portions facing one another. 
j8. Physiology. 
(1) Reproduction and Embryology. 
New Case of Basigamy.f — M. P. van Tieghem calls attention to 
the phenomena of fecundation in Zamia, as described by Webber,* 
which furnish a fresh example of basigamy, i.e. of the reversal of the 
poles in the male prothallium. 
When the pollen-grain germinates at the summit of the nucellus in 
the pollen-chamber, the large apical cell elongates at first into a tube 
which enters the nucellus, but soon deviates laterally, and continues to 
grow at a tangent to the side of the nucellus at a short distance from 
the surface; not only does it not approach the archegones, but it 
gradually increases its distance from them. The tube then ceases to 
grow, but its basal extremity, to which the extine of the pollen-grain 
still adheres, and which encloses a stalked antherid, curves towards the 
base, enters the nucellus vertically, and descends in it to a short distance 
from the neck of the archegone. It then bursts, in order to set at liberty 
its two antherozoids, one of which penetrates into the oosphere and 
produces the ovum. 
Embryology of Ranunculus.§ — Prof. J. M. Coulter reports the 
results of a series of observations on the origin and structure of the 
embryo-sac in several American species of Ranunculus ( R . septentrionalis , 
multifidus , and abortivus). Among the more important arc the following. 
In the young microsporange a plate of hypodermal cells becomes 
distinctly differentiated by means of their enlarging radial diameter and 
prominent nuclei. This plate of cells the author regards as the arche- 
spore. In the development of the megasporanges ( R . septentrionalis) a 
single hypodermal cell frequently represents the whole of the arche- 
spore, though in many cases the archespore is formed of a group of 
cells. In R. multifidus the strong development of the antipodal cells is 
a notable feature, as also the general insignificance of the nuclei of the 
egg - apparatus, the synergid nuclei being especially small. 
* Bot. Gazette, xxv. (1898) pp. 115-6. 
f Journ. de Bot. (Morot), xi. (1897) pp. 323-6 (1 fig.), 
j Cf. this Journal, ante , p. 98. 
§ Bot. Gazette, xxv. (1898) pp. 73-88 (4 pis.). 
z 2 
