MANORANJAN MITRA 59 
flowers show the presence of this fungus. The infection begins from the tip of 
the floret and gradually the whole spikelet gets infected. From the first 
scattered infected spikelets the attack spreads to those in the neighbourhood, 
and in a badly infected ear very few normal grains are formed. When once the 
ear is weakened by the disease, other fungi also make their appearance. An 
infected flower shows a tuft of black mould at its tip, and inside mycelium is 
found in the ovary and anthers. Plate I, fig. 3, shows an ear which was 
inoculated in a few places. 
3. THE ECONOMIC IMPORTANCE. 
The organism appears to cause considerable damage to the leaves and ears 
of bajra and affects the growth and production of sound and healthy grains. 
It hinders the assimilation of carbon dioxide by the leaves and thus the plant is- 
starved to some extent. Further information as to the amount of damage it 
does to the crop in years when the attack is severe is required. 
4. THE MORPHOLOGY OF THE FUNGUS ON THE HOST. 
Mycelium. The mycelium consists of septate hyaline hyphe which 
ramify in the tissues of the host. It is olive brown in colour where conidio- 
phores are given off. It is both intra and inter-cellular, and is found in all 
parts of the diseased tissues, even in the cells of the endodermis, sclerenchyma 
and vessels. Haustoria are not present. 
Conidiophores (Plate II, figs. 1 and 2) are present in greater number in the 
central dead portion of the spot and they gradually get lesser and lesser towards 
the margin. ‘They come out from the stomata of the leaf blade and midrib. 
They are amphigenous, solitary, fasciculate, rigid, erect, straight or slightly 
nodulose or bent ; simple and 3—5 septate. Rarely they are forked near the tip 
(Plate II, fig. 2a). In colour they are olive brown to dirty brown with paler 
tips which are either swollen or flexuous. The base sometimes is also swollen. 
They measure 68°4—-154 mw long and 5°8—8°7 » broad. 
Conidia (Plate II, fig. 3) are clavate, pear-shaped, or elongated, straight 
or slightly bent, thick-walled, 2-3 septate, light olive-brown to dirty brown 
in colour, end cells lightly coloured and middle one broader and darker. They 
are constricted at the septa and are borne at the tip of the conidiophore in 
groups of 2—5. Very rarely conidia on the sides of the conidiophore below 
the tip are noticed. They measure 25—41°8y x 12°5—20p. 
5. CULTURES. 
Pure cultures were obtained several times from typical leaf spots by 
single spore isolations from poured plates, The spores germinate freely 
