1897 | CURRENT LITERATURE 299 
branches rapidly and invades the tissue longitudinally. In this region of 
branching many “vesicles” are formed. It is thought that these “ vesicles’ 
may be cysts which germinate when they are freed by the disintegration of 
the root. Usually the fungus penetrates deeper than the region of “ vesi- 
cles,” and forms ‘‘sporangioles.’’ These are net reproductive bodies, but 
disintegrate soon after formation. They are formed within cells only, while 
the “vesicles” may be either in cells or intercellular spaces. The fungus 
never penetrates the endodermis, and usually stops with one or two layers of 
cells separating them. It never enters cells which contain no nutritive sub- 
stances, and evades scrupulously those which contain such substances as 
tannin and resin. It seldom enters cells containing chlorophyll; but in a few 
cases where aerial root cells contained chlorophyll on one side, the endophyte 
was found to occupy the other side of the same cells. The fungus nourishes 
itself with the starch grains of the infested cells and those adjacent to 
them. This loss of starch marks the only er detrimental effect in the 
host cells. 
The systematic affinities of the egrets! te are absolutely unknown, 
although several authors have describe or some similar form. Jansen 
claims»that none of the forms so meats can be the one which he pre- 
sents. There is variation in the structure of this endophyte in different hosts, 
but the “guest” seems to maintain its identity sufficiently throughout its 
various habitations. The slight morphological differences do not necessarily 
indicate physiological differences. 
The author thinks the association of the endophyte with its host one of 
mutualism (“commensaux”). He likens it to such conditions as exist 
between Rhizobium and inal root tubercles of the Leguminose, and Saccha- 
romyces Kefyr and Bacillus Causasicus. The endophyte evades free oxygen, 
as is shown by its aversion to chlorophyll cells. The host plant gives it a 
hiding place, and it is also furnished with food in the form of starch. The 
nuclei of the host cells in which the “ sporangioles”” are breaking down 
become very large and divide rapidly, giving evidence of being well nour- 
ished by the nutritive matter of the “‘sporangioles."” The host cells use a 
large part of the eng ae compounds of the “guest.” Experiments upon 
asad, plants show that they grow best when their roots are ee by the | 
Prince LITERATURE has received a notable adilition we the recent 
Contribution of R. Lauterborn® upon diatoms. Various species of Surirella 
and © 
_ form very favorable objects for the study of centrosomes, 
- since these bodies can readily be seen in Surirella even in eee living cond- Aves 
| _tersuchangen ier Bau, Kernteilung und Bewegung der Dia tomeen 5 + Aus dem | 
Z00log 
tut der Universitat ee Leipzig, — 
