Brier ley ,— The ‘ Endoconidia ’ of Thielavia basicola , Zopf 485 
investigation it was consequently felt very desirable to make as many 
observations as possible upon Thielavia in the living condition, and to 
use fixed material for confirmatory work. 
Differential intra vitarn staining by the prolonged action of very 
dilute aqueous solutions was largely employed. The fungus was grown 
principally upon banana or potato media, usually solidified by the addition 
of one to three per cent, agar; and that for preparation fixed in situ with 
either Bouin’s fluid or weak Flemming’s fluid. Alum haematoxylin with 
either acid fuchsin or Congo red was the stain giving the best results. 
Origin and Growth of the Conidiophore. 
The peculiarly shaped mother-cell or conidiophore arises from the 
middle region of a cell of the mycelium as a minute protrusion bounded by 
a very delicate and hyaline membrane. This point of origin, although 
perhaps not absolutely constant, contrasts sharply with that of an ordinary 
hyphal branch which is at the anterior end of the cell. Each cell contains 
a single nucleus which is minute, and appears either as an aggregation 
of deeply staining granules, or is well defined with granules often in 
immediate proximity. 
An appreciable time after the inception of a conidiophore the nucleus 
of the parent cell divides, and one of the daughter-nuclei passes into the 
protrusion. The protoplasm in the latter is clear and has a higher refractive 
index than the vegetative cell contents. In its development it assumes 
a slightly curved finger-like form and soon is cut off by a transverse wall 
immediately above its base. The protoplasm becomes more dense, but 
rarely granular, and the nucleus occupies a position away from the tip 
of the cell. 
When mature the conidiophore presents an exceedingly characteristic 
appearance (PL XXIII, Fig. 1), being slightly bulbous in its basal portion, 
and possessing an elongated, tapering, or almost linear apical region. The 
cytoplasm is often slightly alveolar or flocculent, occasionally minutely 
granular, and rarely slimy or homogeneous. Large vacuoles are usually 
present, which, particularly towards the upper region of the cell, not infre¬ 
quently contain oil-globules. The nucleus lies in the basal portion of 
the cell. 
Formation of Conidia. 
The nucleus in the conidiophore apparently divides in a mitotic 
manner, and one daughter-nucleus remains in the original position, whilst 
the other passes to the apical region of the cell (PI. XXIII, Fig. 2). Here 
the protoplasm shows a barely perceptible increase in density, the vacuoles 
contract slightly in size and frequently contain a greater number of oil- 
globules. This apical region containing a nucleus slung in the protoplasmic 
