ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
205 
hairs by poisoning. In Peperomia scandens the glandular hairs have 
lost their power of excreting, and are simply organs for the absorption 
of water. In their perfect condition these organs serve as an apparatus 
for regulating the araouut of water in the plant. 
Haustoria of Lathrsea.* * * § — Dr. *E. Heinriclier has again studied in 
detail the structure and the adaptation to their function of the haustoria 
of the two species of Lathrsea , L. squamaria and clandestine,, which 
present some differences in the mode in which the liaustorium enters 
and penetrates the tissues of the host-plant. In general terms, the origin 
and development of these organs in Lathrsea correspond altogether 
with the same processes in the Rhinanthidese, and the author agrees 
with those who regard this genus as more nearly allied to the Scrophula- 
riacese than to Orobanche. The following are the chief points of affinity — 
The structure and development of the ovule, especially the embryo- 
sac, with its characteristic diverticula, which appear after impregnation. 
The structure and form of the embryo. The mode of attachment of the 
parasite to the host-plant. The radical apex of the embryo does not 
become the primary liaustorium, as in Orobanche , but developes into the 
root, the haustoria .appearing on it as secondary formations. Various 
points in the structure of the root and of the haustoria, and in the de- 
velopment of the haustoria. The arrangement and course of the vascular 
bundles. The presence of glandular hairs in the cavities of the rhizome- 
scales in Lathrsea, and in the leaves of the Rhinanthidese, while no such 
structures occur in Orobanche. In all these points Orobanche presents 
a different type of structure from that which is common to Lathrsea and 
to the Rhinanthideae. 
Vegetative Organs of Vanda. f — Mr. H. H. Dixon describes the 
anatomy of the stem and roots of Vanda teres. The velamen of the 
root is composed of two layers, the outer consisting of fibrous tracheids, 
the inner of much thicker- walled pitted elements. The root-caps of the 
growing points in a state of rest are clothed with a thick cuticle, which 
is not the case when they are in active growth. 
Root-Tubercles of the Soja-Bean.J — Having noticed that the roots 
of Soja hispida, when grown in Europe, do not produce tubercles, while 
they do in their native country of Japan, Prof. 0. Kirchner devised the 
expedient of infecting them by growing them in soil obtained from that 
country. The device succeeded, and they produced abundant tubercles, 
thus showing that these must be caused by a microbe present in the soil. 
In anatomical structure the root-tubercles of Soja present the greatest 
resemblance to those of Phaseolus ; the special microbe which produces 
them the author proposes to call Bhizobacterium japonicum, substituting 
this generic name for Frank’s Bhizobium. 
Variation-Curves and Surfaces in Plants. §— Prof. F. Ludwig has 
laid down a series of curves, on the principle proposed by Galton, for 
* Beitr. z. Biol. d. Pflanzen (Cohn), vii. (1895) pp. 315-406 (7 pis.). Cf. this 
Journal, 1893, p. 500. 
t Proc. R. Irish Acad., iii. (1894) pp. 441-58 (4 pis.). See Bot. Centralbl., lxiv. 
(1895) p. 131. 
t Beitr. z. Biol. d. Pflanzen (Cohn), vii. (1895) pp. 213-24 (1 pi.). 
§ Bot. Centralbl., lxiv. (1895) pp. 1-8, 33-41, 65-72, 97-105, 248-9 (2 pis.). 
