450 
Morphologie, Teratologie, Befruchtung, Cytologie. 
outbreak of disease, to the root-system of Santalum album, its para- 
sitism was considered and its haustoria examined. It was found 
with surprise that these organs had not been described and large 
collections were raade of them attached to different hosts in the 
typical sandal region of South India. In the course of this investi- 
gation it was discovered that some of the Olacaceae are also green 
hemi-parasites and that their roots are provided with similar haustoria 
(Cansjera Rheedii, Olax scandens, Ximenia americana and Opilia 
amentaced). The haustoria of these trees and climbing shrubs are 
much more complex bodies than that described for Thesium, and it 
was decided to study them in succession, Santalum album being 
selected first because of its economic importance and the abundance 
of material available. 
After a general description of the plant, its habitat and geogra- 
phical ränge, the root-system in seedlings and in mature plants is 
discussed, and it is pointed out that the scarcity of root-hairs and 
the abundance of active haustoria suggest a very complete root- 
parasitism. A series of stages in the development of the haustorium 
are then described and the fact is noted that many of the haustoria 
are aided in their attacks on other roots by the presence of a well 
defined gland. This gland, hitherto unknown in the haustoria of 
root-parasites is carefully described. The haustoria appear to attach 
themselves readily to other substances than roots, and cases are 
figured of attacks upon pebbles, leguminous nodules and, in one 
instance, the chrysalis of a moth. The structure of the haustorium 
varies according to the substance attacked and the differences 
between those found on monocotyledon and dicotyledon roots are 
noted. It is further seen that, in dicotyledons, the structure of the 
root attacked exercises a considerable influence upon that of the 
haustorium. 
It has thus been considered necessary to study a very large 
number of sections to obtain a just idea of the typical haustorium. 
It is further pointed out that, the haustorium being a bilateral 
organ, sections must be studied in three different planes, and a 
plate of diagrams is added to illustrate this. The mature haustorium 
is studied in detail, the tissues being dealt with under the headings 
Cortex and Nucleus, Vascular System, and Sucker. Cases of irregulär 
Penetration are then described and it is pointed out that the irregu- 
larities are chietiy dependent on the distribution of sclerotic bands 
in the host’s root. The resistance offered by the root attacked is- 
then considered and a summary prepared of the means adopted by 
it for self-protection, such as the formation of cork and sclerotic 
cells, the filling of vessels and cells with gummv substance and the 
formation of thvloses. A special case in which haustoria are found 
attacking the roots of sandal itself is more carefully considered and 
illustrated. 
Appendices contain a list of sandal hosts and a list of some of 
the more typical plants of the true sandal zone in Mysore. 
C. A. Barber. 
Künstler, J., L’origine du centrosome. (C. R. Ac. Sc. Paris. 
CXLIV. p. 45—46. 7 Jan. 1907.) 
Le centrosome semble etre, pour l’auteur, le centre cellulaire 
primitif. Derive, dit-il, de la specialisation d’une spherule plasmique 
ordinaire, il parait avoir precede le noyau comme element morpho- 
