174 THE AMERICAN MONTHLY [Jun 
is more or less disorganized, the outer wall of epidermal 
cells becomes thickened and forms a centripetal ingrow- 
ing membraneous body, which the pedicel of the hausto- 
ria must push inward. After this growth into the cavi- 
ty of the cell, the haustoria is surrounded by a sheath 
which consists of the plasma membrane of the host plant, 
and unchanged cellulose. (Bot. Gaz. 29: 153.) 
CENTROSOMES.—The subject of centrosomes finds a fur- 
ther exemplification and confirmation by 8. Yamanouchi. 
He was unable to find the centrosomes in the resting nu- 
clei of the pollen mother cells of Lilium longiflorum but it 
was possible to find them in the first stages of the divi- 
sion of the cell. He frequently found the centrosomes 
either on one or both poles. The material was fixed with 
Flemmizg’s solution, washed with water, 70 per cent of 
absolute alcoho] and chloroform, and imbedded in paraf- 
fine. Materials were stained with Bohmer’s Hematoxy- 
lon and Flemming’s orange method. (Beihefte Bot. Cen- 
tralblatt, 10: 301. 1 pl.) 
ARE THERE BACTERIAL DisEASES OF PLANTS ?—Dr. 
Erwin F. Smith has just distributed separates of his four 
papers on the above topic published in the Centralblatt f. 
Bakt. Parasit.u Infekt. The papers are of unusual excel- 
lence, showing the normal pathological conditions of the 
plants affected by various organisms, the figures being 
made from photographs. Dr. Smith discusses the evi- 
dences pro and con of the various diseases investigated — 
by himself with some of the collateral work carried on by 
other investigators. Dr. Smith is well-known for his care- 
ful investigations along the line of pathology and his 
many experiments leave no question of the diseases dis- 
cussed by him being caused by micro-organisms. It is 
strange that so noted an authority as Fischer should doubt 
that there are any bacterial diseases of plants when these 
facts are well recognized by most plant pathologists. 
