gr0] CURRENT LITERATURE SS a 
logical categories. He believes that there are “three stereotyped, fixed 
categories of organs, viz., shoot, leaf, and root,” and that there can be no 
others. “There can be no room in that region of the vegetable kingdom . 
above the level of the homogeneous thalloid types for any organ which is 
neutral, intermediate, or undifferentiated in character.” Incidentally the 
author furnishes proof, which he says is unequivocal, ‘that the normal rhizo- 
phore has the morphological value of a shoot.” This conclusion we are ready 
to accept, in the absence of any better one, but it is late in the day to defend 
rigid categories, and to decide what can and what cannot be. —J. M.C. 
New genus of flagellates—GArDNER®™ has described a new genu 
flagellates (Leuvenia) whose unusual combination of morphological Feitares 
famil 
growth, and palmella stages are known. In the growth and mature stages 
_ the nuclei and chromatophores are inconstant in number, and in the motile 
peers contractile vacuoles occur in both anterior and posterior ends, and 
“pyrenoids, gullet, and stigma are absent.” The chromatophores divide by 
nstriction, remain attached for some time by delicate cytoplasmic strands, 
and are irregular in shape and size.—J. M. C. 
Diurnal periodicity in the nitrogen content of leaves.—Investigations 
hitherto have tended to establish a diurnal periodicity in the nitrogen content 
of leaves, the fluctuation showing a greater content in the morning than in the 
evening. CzApEK, however, in his Biochemie states that such investigations 
should be more comprehensive. With a view to supplying this need, OrTo 
even in different stages of development leaves of several different species have 
a greater nitrogen content in the morning than in the evening. They also 
found a gradual decrease in the nitrogen content from spring to autumn.— 
YMOND H. Ponp 
vr 
*® GARDNE fe oe desire a new genus of flagellates. Univ. Calif. Publ. 
Bot. 4297-106. e 14. 
ee a, Da. R., io ee bok D., , Beitrige bud Abuabeae cae Sackwuse 
Tune d. 
r Cy 
lichen “cage Ne von ‘Stickstofiverbindungen aus den Blattern. Landwirtsch. 
Jahrb. 39:167-172. x 
* GARDNER, N. : — Chlorophyceae from California. Univ. Calif. Publ. 
Bot. 3: *371-375. pl. 14: 1909. 
