114 Disease of Olive and Orange Trees. By W. G. Farlow. 
other bodies of a more complicated nature. Plate OL., Fig. 8, a, 
represents the jpycnidia, which are quite numerous in the spots, 
both on the leaves and the stems. Their general shape is sphe- 
roidal. They consist of a membranous sac of the same colour as 
the darker parts of the mycelium, in which are contained the 
small bodies, which are represented as being discharged in 
Fig. 3, h. Their average diameter is '04 mm. In general ap- 
pearance the pycnidia resemble so closely those with which every- 
one is familiar in other Pyrenomycetes, that any further description 
is unnecessary. 
Stylospores. — In examining the larger black spots on the 
stems of the olive, other bodies are seen, — the stylospores, to adopt 
Tulasne's nomenclature. They are represented in Fig. 1, a, and 
resemble flasks, whose long necks project beyond the mycelium, by 
which they are surrounded. They may be recognized by the 
naked eye, and clearly seen with a hand-lens, as the black pro- 
jecting necks are tolerably conspicuous. To obtain a good view of 
them, some of the larger black spots must be picked to pieces, and 
the fragments treated with caustic potash, and afterwards hydro- 
chloric acid. The shape of the separate flasks is quite variable. 
The central portion of Fig. 1 represents one of the more regular, 
where, starting from a somewhat contracted base, there is a regular 
swelling of the central portion, which again diminishes into a 
rather long neck of uniform size. In some cases, the flask, instead 
of being straight, is flexuous with two swellings, the upper one 
being smaller than the lower. Others, still, fork, and usually one 
branch is much more obtuse than the other. The size of the flasks 
varies very much ; but even in their younger states they can 
generally be distinguished from the pycnidia, by being less inclined 
to a spherical shape. The height is as variable as the outline. 
Some of the smaller are '15 mm. high ; others — and they are 
nearer the average — are '4 mm. The wall of the flasks is com- 
posed of dark-coloured cells, which are longer in the direction of 
the axis of the flasks. 
In some cases the cells composing the wall of the stylospores 
grow outward, so as to form papillae ; and as the mycelium at the 
base generally sends up branches around the flask, it is only by a 
careful dissection that the base can be clearly seen. At first the 
mouth is closed, and there is a depression of the cells at the centre ; 
but later they spring back so as to form round the open mouth a 
circle of slightly reflexed teeth, whose tips are perfectly hyaline. 
The neck of the flask is hollow ; but in the swollen portion spores 
are borne. They are oval, and divided into four parts by cross 
partitions. They are not contained in asci, but are attached to 
short filaments which line the surface of the base and lower portion 
of the sides of the flask. They escape readily through the open 
